Have a Dell XPS 1330 with Vista Premium (bout 2 months old) with all the MS updates.  Run Bitdefender firewall.  I recently tried to update to Flash 10 and now flash is not longer recognized and working in Firefox.  Have tried the following

1.  Security level for all aspects of Flash in windows, system32, macromedia folder are set to "all" for everyone.

2.  copied the dll to Mozilla plug in folder

3. ran the flash utlity update

5. uninstalled and reinstalled with firewall/antivirus turned off

6. UAC is turned off

 

Anyone have any suggestions?  At this point I am ready to downgrade to XP, VISTA has been a royal pain and will never do again.