Try to start Firefox in Safe mode. This mode disables all extensions, user customizations, hardware acceleration, etc. temporarily for diagnostic and troubleshooting. If Firefox works find in Safe Mode, then this is likely an add-on issue. Restart Firefox in normal mode, then type "About:addons" (without the quotes) in the address bar. Disable your extensions one by one, restarting Firefox between each one, until you find the trouble maker. Once you do, you can disable that add-on and report the issue to that add-on's developer.

A few other basic trouble shooting things you can try is this: Run all Windows Updates, install all needed service packs, etc.

Update your graphics driver (Firefox uses your graphics card for some rendering, and an out of date graphics card driver can cause problems. https://support.mozilla.org/en-US/kb/how-do-i-upgrade-my-graphics-drivers.

Update all your plugins (Flash, Java, etc.): http://www.mozilla.org/plugincheck/.

Since this rather detailed response arrived just seconds after my post, I suspect that it's a generic troubleshooting procedure and doesn't really address my problem. Sorry, I'm just a grumpy old man.

I've never used Safe mode before but it looks rather threatening. If I restart in safe mode with add-ons disabled, will they be there when I restart normally?

I'm hesitant to experiment with disabling things at random since I can't yet predictably reproduce the problem, so I can never be sure what, if anything, fixed it. At this point, unless others have experienced the same problem and have found a direct solution, I'm going to assume that it's a bug, that it gets noticed, and that those who are good at troubleshooting will find a fix. In the mean time, I'll live with it.

But thanks for the response. I'm glad someone, or something, is listening here.

I'll add (new discovery) that when the scroll wheel stops working on the web pages, it still works to scroll through menus, like a long bookmark list.

Does that help with a real diagnosis?

Yes, if you restart in Safe Mode, so long as you don't tell Firefox to permanently disable your add-ons (by not checking the boxes that appear when you start Safe mode) everything will be back to normal when you start firefox normally. It is a temporary diagnostic mode to see if user changes, add-ons, etc are interfering with normal operation of Firefox.

Would you mind also trying the other steps such as Windows updates, updating plugins, etc?

Do you have a PDF (Adobe Reader) document open in another tab when that happens?

I doubt that I have a PDF open in another tab because I don't use the PDF plug-in to Firefox. When I go to a web site with a PDF and click on it, I get a pop-up that asks if I want to open it (I use Foxit) or save the file. I often have a PDF open when I'm on a web site however. I just opened one and everything's still OK. Then I went to a web site where I clicked on a PDF and told it to open it with Foxit, and things are still OK.

Like I said, I haven't yet found anything that consistently makes it happen.

As for updates, I really want to know if there's anything specific that might cause this problem. I don't like to make updates, not even Windows updates, unless I see that the update either solves a problem or gives me a feature that I really need. I look at the Windows updates and they all seem to be about security, which isn't a problem here. In the case of installing the new Firefox, I was getting tired of web sites telling me that I had an unsupported web browser (though usually I could get what I wanted). I'm NOT going to just let Windows do what it wants with my computer. I depend on it too much to do that.

Could it be that something that Firefox needs is running out of memory after browsing for a while? Is there something I could check for that? I think I have 1 GB of RAM in this Pentium 4.

Here's a clue. One forum that I visit regularly seems to cause the scroll wheel hang-up most times that I'm on there. It's a technical forum, no porn, no embarrassing :noises or pictures. Perhaps someone who likes to take web sites apart to see what makes them tick could find something suspicious there.

http://forums.presonus.com/forums/

I just noticed that I don't (at least this once) need to close and re-start Firefox in order to get the scroll wheel working again, I just need to close the "killer" tab. After having it quit on the PreSonus forum, I opened this one and it's working again.

It's easy to blame a particular web site, of course, but I haven't determined yet that this is the only web site that hangs the scroll wheel. But, though it's not totally verified, my sense is that the problem doesn't occur when I'm just reading, but that it occurs after I post on that forum, though not always immediately after I post.

I hate these problems that I can't make occur at will. It makes troubleshooting or analysis all the more difficult.

I updated to Version 12 when I saw it was available and still I have the same problem, most often with the web page (PreSonus) listed above.

Plug-ins got checked when the new version was installed and it was happy with all of them (very few), and Windows is up to date.

Any further suggestions?

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.org/kb/Safe+Mode

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes
• https://support.mozilla.org/kb/Troubleshooting+plugins

OK, I tried Safe mode, disabled all extensions and add-ons, and I have only the default theme. The PreSonus forum still kills the scroll wheel after some reading. No need to post to make it quit.

What I did notice with this experiment is that while I can still scroll the Bookmarks list with the mouse wheel, scrolling in the Extensions list (I think this is the actual browser) dies along with web page scrolling.

Could it be a memory thing? I'll check memory usage with the Windows Task Manager next time it hangs.

OK, I give up. No working solutions so far.

If I install an earlier version (I have 6.0 as well as the 3.something that I updated this computer from) will it find my bookmarks and passwords? Or will I need to save something first?

Oh, I suppose I should add that it updated itself to 12.0 and the problem persists. I really want to go back to an older version that works on this computer.

I've installed 10.0.4ESR and I believe the problem is solved, but I'll need to spend more time with it to be sure. Thanks to mrbrubeck in another forum who pointed me to this "downgrade" release.

If I'm missing any great features by not having the latest and greatest, I haven't missed them yet. ;)

It may be too soon to know for sure, but I think that my problem, loss of the mouse scroll wheel in web pages after visiting one or two particular web sites and browsing a while, is not a memory leak issue as some have suggested, nor a funky extension, but rather a mouse driver issue. I've been using an IBM branded mouse with the driver that came with it rather than the standard Microsoft driver. removed the IBM mouse driver (and mouse) and installed a store brand mouse using the standard Windows XP mouse driver. This hasn't hung up yet in a couple of days of use.

If I have a memory leak problem, I don't think I've encountered the result of it yet. The program (currently using 10.0.4 ESR) seems to be stable, no crashes, no hangups, and, hooray! no mouse scroll wheel problems.

I miss the "center button magnifies" function with the IBM mouse driver (this also works with the generic mouse when the IBM driver is loaded) but I'd rather lose that function than lose the scroll wheel and have to quit and restart Firefox to get it back.