You could experiment with turning Firefox 4 hardware acceleration on and off, does that have any affect on the problem ?

Other than that I am not personally aware of major changes between versions that would cause problems, but no doubt someone will make suggestions. You should certainly try this out using Firefox Diagnose Firefox issues using Troubleshoot Mode (in Firefox 4 I think that does disable hardware acceleration)

John99 Thank you for your response. I have already tried that and it makes no difference. I have been working away at this for days and I am no nearer now to to finding an answer than I was when I first noticed this problem. Interestingly with FF4 installed I was also unable to use the "view in browser" facility in Dreamweaver. It did all kinds of weired things. Not least the prevention of IE opening any pages in Dreamweaver. I am certain that there is a problem with the pop blocker action and it's behavior in FF4. I have deleted FF4 and reinstalled FF3 and everything works perfectly, even Dreamweaver is functioning properly again. I need to find out and get the problem resolved, because anyone visiting my site using FF4 will find content missing and some functions not working. This problem is present on the internet, and the local server.

Beeza

I have opened your site with Firefox 3.6 and 4 simultaneously and although I do not see any strobing or odd effects the daily content part is not displaying text in Firefox 4 but it is in Firefox 3.6.

Obviously your code is interacting with the browser as you actually display the browser version, and have correctly identified whether I am viewing with firefox 3.6 or 4.0

On the assumption that the problem may be with the coding of your website, it may be worth posting on the MozilaZine Web Development / Standards Evangelism forum someone there may well quickly find an answer to the problem.

Note it is possible to have more than one version of Firefox installed, if you then use separate profiles for each, and make use of the -no-remote command switch it is even possible to run two versions side by side.

• see http://kb.mozillazine.org/Testing_pre-release_versions#Installing_multiple_versions
• and http://kb.mozillazine.org/Opening_a_new_instance_of_your_Mozilla_application_with_another_profile

Any other problems you have with Firefox may relate to interactions with differing extensions. Post back with how you get on.

Thank you for your continued interest. I will certainly keep you informed of any progress that I make.

John99 The concencus on the site that you directed me to seems to be that it is a code problem. This stems from the way inwhich FF4 parses (what ever that means). I have little knowledge of code. I construct my pages with Dreamweaver which is WYSIWYG. As I put my site together Dreamweaver does all the coding building for me. One thing I did not mention before. FF4 totally trashed the "View in browser" facility in Dreamweaver. FF4 did some really wierd things to my computer, so much so that I thought I had a virus infection. I am not impressed with FF4 at all. An upgrade is supposed improve performance not degrade it's capabilities. No doubt I shall be hung drawn and quatered by some for my views. I really cannot see how FF4 can be a superior browser given what I have experienced. IE may have many faults, but it does render my pages. correctly.

Beeza

If you can not fix your code yourself to be HTML 5 compliant, then you could mention on your webpage the specific problem with Firefox 4.

You already have comments about browser use on your webpage . see You could add a line to the effect that some features do not at present work in Firefox 4 unless the HTML 5 parser is disabled.

A workaround:Disabling the HTHL5 parser
The HTML 5 parser in Firefox 5 may be disabled by toggling the preference html5.parser.enable off. You could try that yourself. (I did and it works), and possibly suggest users of your site may like to try that. (but include a reminder to toggle it back on afterwards)

You may yet get further help in fixing the missing close tags, or whatever the problem.

Potential Firefox 4 bug ?It does occur to me however that if your webpage is valid as "CSS level 2.1", then Firefox 4 should be able to render it correctly, without a user needing to manually disable the HTML5 parser. I would have thought that such a problem should only occur in Firefox 4 if the page declaration was incorrect. (Your page does seem to validate ok - although I am guessing your Dreamweaver is getting past its sell by date).

The above thought leaves me wondering if some other Firefox 3.6 to 4 problems such as very slow performance may relate to the HTML5 parser, and maybe therefore it could sometimes be a worthwhile troubleshooting step to disable it. ( HTML 5 parser does not disable in Firefox 4 Safe Mode, although hardware acceleration does) Any comments anyone ?

Hello again John99 Thank you once more for your most helpful advice. "A workaround:Disabling the HTHL5 parser The HTML 5 parser in Firefox 5 may be disabled by toggling the preference html5.parser.enable off. You could try that yourself. (I did and it works), and possibly suggest users of your site may like to try that. (but include a reminder to toggle it back on afterwards)" 'The problem with that as I see it is that most casual users would not have any idea how to do that. Speaking for myself, I for example was unaware that it was possible to do this until you mentioned it.

I really need to find some way of making the code compatible. I am not totally ignorant of code commands, but javascript is completely alien to me, The script in question was a cut and paste script. I am quite happy to own up to that.

You may yet get other comments on this site or the Mozilazine site, and maybe it will be decided the Firefox 4 behaviour is not ideal, in which case that may change.

You could as a temporary measure add an explanatory page to your website and explain how users may temporarily disable the Firefox 4 HTML5 parser, if they want to see your sites feature.

My js knowledge only runs to writing the simplest scripts or understanding some code fragments. If you are interested in learning more try a web search, one site with explanatory material including free interactive tutorials is http://www.w3schools.com/js/default.asp

I may even try the new Firefox 4 web console against your site at some stage; if I do and notice the cause of the errors I will post back with info.

See also:

• http://forums.mozillazine.org/viewtopic.php?f=25&t=2164637

Why is ff4 not working properly all of a sudden with my banks website which is USBank also ebay doesnt load properly and also another common site Sprint. What the Heck firefox?? So much for the "improvements". Images will not render properly. And IE9 and Opera both work fine. Do I have to go back to previous version or are you gonna work this out please ??

Hi Landmarkcm,

You would probably do better to start your own thread about your own questions.

You may go back to Firefox 3.6 relatively easily if necessary. Firefox 4 may have compatibility issues with some add-ons, other problems may only affect a minority of users.

For the benefit of those of you that might not be able to visualise what my problem is I have uploaded some screen shots so that you can see what FF4 is doing to my web pages. The first to images show the first page of my site. The first image is how it appears in FF4. The second image shows how it appears in FF3 and IE. The third image shows how another page appears in FF4, and the forth image shows how that page appears in FF3 and IE. On the Forth image you will see an image of Private Eye which when mouse clicked will open an internal pop up that shows that image in greater detail. It does this correctly in FF3 and IE, but in FF4 the image trys to open but flashes on and off just like a strobe light. The flashing cannot be stopped unless the page is closed. The page shown in image 5 renders properly in FF4,FF3, and IE. However, in the bottom left hand corner there is again an image that activates an on click event to show that image in greater detail in an internal pop up. That to flashes like a strobe in FF4. In FF3 and IE it works correctly. Clearly there is something very wrong with FF4. If you wish to view the images open in a new tab.

John99I have at last resolved the problem of the missing text in the panel at the top of the index page. It is now rendered correctly in FF4. If you view the code on that page I have removed everything between line 226 and line 233. I have not put the revised code page on line yet. But I will be doing so later today. How or why this should have resolved the problem I do not know. All I have to do now is to start work on the other to problem pages. I would like to sincerely thank you and everyone else that took an interest in this problem.

You should use getFullYear() instead of the deprecated getYear()

• https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Date/getYear
• https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Date/getFullYear