Try to update to Firefox 12. Does the issue still happen there? (Firefox 3.6 is no longer supported or secure).

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 fine 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Update your graphics driver (Firefox uses your graphics card for some rendering, and an out of date graphics card driver can cause problems.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/.

Download and Install MalwareBytes Anti-Malware, run a full Scan. http://www.malwarebytes.org/. This helps check that there are no viruses on your computer causing issues. You can uninstall this program after you clean off any infections.

It's true, my drop down box doesn't work in FireFox, but works in IE and Chrome. I don't have any add ons installed.

FireFox has been buggy in the last 2 weeks. Silverlight in Hotmail crashes all the time.

Asp.net drop downs are not clickable unless you hover over the upper left portion in the sweet spot and click at the right second.

No add ons and i'm up to date. Or at least the FireFox home page says I am on version 12

Thanks, Nick