Firefox 8 Going Bananas

Question

After upgrading to Firefox 8 (final build), some new issues happen ''intermittently'', some of them:
1. Missing bookmarks in Bookmark menu and the Bookmark button (opening Bookmark Manager shows everything still exist there).
2. Missing Auto Complete entries (previously entered text wouldn't show in any text field).
3. Add-ons Manager wouldn't load.
4. Cycling through open tabs using CTRL+TAB (+SHIFT) make an empty dialog (just with some number & OK button) appears.
5. Trying to close Firefox 8 with multiple open tabs resulting in an empty dialog box with OK and Cancel button, but clicking either one yields nothing (the dialog persist). Need to click the close ("X") button.
6. When using DownThemAll, if there is a non-resumable download, trying to close it resulting in same dialog box as in #5, even after closing all open windows and tabs. Need to kill firefox.exe process tree.
7. When trying to download something (clicking on a link), an error message appears (the same dialog box when a download using built-in downloader is interrupted).
8. Opening about:support page yields an empty page - just tables with no data (just realized when I want to collect Troubleshooting Info below).
... and others, which I'll update later.
-My workaround is just to close Firefox (if cannot, end the firefox.exe process tree in Task Manager), wait for a bit, and open Firefox back (& hope everything will be okay).
Notes:
1. This problem occurs after upgraded to Firefox 8.
2. I don't use Aurora, nightly, beta; just stable release channel.
3. I only have a few add-ons, namely AdBlock Plus, DownThemAll, etc. (cannot check, Add-ons Manager cannot be opened now - DTA is downloading a non-resumable file, so cannot close Firefox).
Regards,
-Musafir_86.
P/S: It seems since Firefox 8, DTA always cannot resume (and of course no 'multi-parting' a download to accelerate it too), even from a server that's known to support multi-connection before.
P/P/S: To be clear, NONE of above issues happen when I was on Firefox 7.0.1.
P/P/P/S: I'm writing this from IE9.

Answer 1

-I have added some images to better describe the issues:
SS1: 'Phantom' dialog box which clicking "OK" or "Cancel" yields nothing (need to click the "X" button to make it go away);
SS2: Downloading issue (cannot download anything - this error will pops up);
SS3: about:support page is empty without data.
Regards.