overview

a corrupted profile is the cause of much weirdness in firefox. I wish it weren't this way, but it is. and with many of the bug reports in mozilla.org, this is what they suggest you do to fix Firefox. and it works in many cases.

steps

1. start firefox
2. backup your bookmarks: Bookmarks, Organize Bookmarks, Import and Backup, Backup.
3. click the "My Documents" button and remember your choice.
4. click OK.
5. close all instances of firefox and its download manager window(s).
6. start a Windows Explorer ( windows-logo-flag-key]-E ) and browse to XP C:\Documents and Settings\yourUsername\Application Data\Mozilla\Firefox\, or Vista/7 C:\Users\yourUsername\Application Data\Mozilla\Firefox\. please note that Windows Explorer ≠ Internet Explorer.
7. delete the firefox folder.
8. start firefox.
9. it will try to import your IE favorites, and will probably have a fit if you have a lot of them like I do. click continue if it does, and check "don't bother me again". This is not supposed to happen, but Mozilla chose to write this code in javascript instead of C++. I hope they fix it soon. process can take 15 minutes.
10. set your homepage in Tools, Options, and other settings you wish, such as restoring tabs on startup.
11. customize the toolbar as you wish. I like small icons, and having the download button, new tab button, bookmarks button, and print button (why they don't include the print button by default I will never know).