Hi

I fully understand and appreciate the wonderfulness of a 404. It told you immediately what you wanted to know - that the site could not be found!

What you are seeing is where the registration and ownership of the site has been passed back to the registry that owns the domain. The site can be found, it is just acting as a advert of the person that owns the URL so they can sell or resell it.

The location bar is working as it should - it is displaying the URL as requested - it is just not the preferred end result. One way you could get round this is using a parental control addon and include the name of the registry in the watch list (or edit the list so that is the only entry). It will stop the page from displaying. An example of the sort of addon you coudl use is (link).

Thanks for the suggestion, Seburo. But I am still somewhat confused, because a) there really is a redirection going on (I type in a URL and get taken to buydomains.com instead--it is not an advertisement parked on the URL, but a redirection away from the URL that I typed). And b) it happens on some of my computers and not on others (on some of my computers, I get a lovely "Server not found" error message instead of being taken to buydomains.com). So I suppose my question is this: what settings did I set (and have now forgotten) on my well-behaved Firefoxes which I failed to set on my badly-behaved Firefoxes? sreimer

Is there any pattern as to the DNS servers used by the computers with the redirect and the ones without? Just in case we need to point the finger at your ISP (or hijacked DNS settings). DNS settings may be in your router, or in Windows, or in Firefox's proxy settings. To check Firefox:

"3-bar" menu button (or Tools menu) > Options > Advanced > Network mini-tab > "Settings" button

The default of Use system proxy settings will use the Windows/IE "LAN" settings. You also could try No Proxy.

Some add-on authors may get paid for doing stuff like this... Here's my suggested procedure for tracking down and cleaning out bad Add-ons. Sorry for the length -- it's not as bad as it sounds:

(1) Open the Windows Control Panel, Uninstall a Program. After the list loads, click the "Installed on" column heading to group the infections, I mean, additions, by date. This can help in smoking out undisclosed bundle items that snuck in with some software you agreed to install. Take out as much trash as possible here.

(2) Open Firefox's Add-ons page using either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Plugins. Set nonessential and unrecognized plugins to "Never Activate".

In the left column, click Extensions. Then, if in doubt, disable (or Remove, if possible) unrecognized and unwanted extensions.

Often a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step.

Any improvement?

(3) You can search for remaining issues with the scanning/cleaning tools listed in our support article: Troubleshoot Firefox issues caused by malware. These on-demand scanners are free and take considerable time to run. If they finish quickly and especially if they require payment, you may have a serious infection. I suggest the specialized forums listed in the article in that case.

Success?

Thank you, jscher2000. I did try setting "no proxy" and also tried turning off addons, but the behaviour continues.

 After my reply to Seburo, I did (should have done earlier) go back and double-check my sense that the different computers in the house were doing different things, and I was wrong: in fact, they are all doing the same thing, and I expect that Seburo is right, and that Firefox is just doing what it is being told to do--presumably by buydomains.com--when I type in this particular erroneous URL.  So I will a) try to remember the correct URL for the site that I was trying to reach, and b) consider the "parental control" addon to prevent seeing the buydomains.com site if I do repeat my mistake.
 Thank you both for your suggestions.