I have also tried un-enabling in Firefox, closing, reopening and renabling javascript, closing, reopening, the problem remains.

JavaScript 

هذا البرنامج لدي به مشكله ...كل ما ارت ان افتح نافذت الموزيلا فير فيكس فتحت لي نافذه تقول لي بان هناك مشكله في تطبيق هذا البرنامج ارجوكم اريد مساعده

Noor, could you please post the reply in English? thank you

Just installed update 3.6.8, javascript still not working.

We've solved it, hard to believe. We are using UMTS-sticks, I use the german provider o2, my wife the german provider 1&1, using vodafone. Look and hear: if we change the sticks crossover, the error changes crossover. Those of you, who can read german, can use this forum: http://www.camp-firefox.de/forum/viewtopic.php?f=1&t=82622. Vodafone compresses the traffic, depending of the APN, you are using. Hard to believe, but it is. Urgs, what a shit. And of course without one word.....

Thanks for your post, Wolfgang I think I'll switch to Opera until Firefox resolves some issues.....

I disabled plugins one at a time and for me the javascript problem was cured by disabling Adblock Plus 1.2.1

Thanks your hint. This problem also occurs with t-mobile UMTS-sticks and effects common websites, that use jacascript (e.g. ebay, google maps). When switching to standard ISDN connection - no problem! I would be very happy, if firefox would solve this in one of the next updates.

After writing a very long paragraph including all that I have tried, in my annoyance, I clicked on one person's rec and clicked that it was not helpful and to my further upset, everything I wrote disappeared! First I cleared cache along with everything else in temp files (overkill but in IE also) as I recalled that I have spent a lot of time with tech support because of a new printer that never was able function (no surprise but I was told they wrote drivers in Aug so worth a try). Then Skype was the trouble-well, it is on my PC but always was so I didn't follow that. "about:config" in address-bar and then image in filters and look for 3 lines which checked fine, Now I have done all of this JavaScript changing and then restart and reset only to be at this awful place where I have lost valuable time but have no more function than that before I started. I simply know and am confident that I have reset and put all back the way it was. This Firefox stuff is great, right? I am extraordinarily uneasy with everyone making all of these suggestions only to get no where. Scary world. I am using XP Professional64bit SP2 which is up to date-new PC bought as a Windows 7 downgrade because it is business PC and couldn't handle anymore adjustment to new programs, etc Good luck to all. Since I still get updates from a problem that was solved 5 years ago and when I try to stop it-I get to an "error 404 page not found" so I cannot say that you can follow me with a solution but I am interested in the outcome. Bye, S

This solution worked for me in FF5. Yet half of the problems started to reoccur after a while. Perplexing to say the least. Yet other issues with adblock 1.2.1 conflicted with IE 7 and have heard of the unblock issue (settings: blocking) staying permanent. Since importing the block list and hearing that it sticks (forever,The no deleting issue....which I have not heard of a fix for that yet...some things just should never become permanent, yet other sites should be permanent. Shutting down Bing perm, for instance, will shut down many news and other video playback in IE, since IE and FF integrate at times, settings stay permanent on the PC no matter what browser you try. Till adblock makes fixes, cannot use it. It causes freeze as well if checking mail in IE LIVE(hotmail). Also causes conflict with start page changing FF to not be my startpage.