Reverted settings after recent firefox update?

[Mike]

After the recent firefox update in F8 I noticed that my carefully changed
settings in Edit -> Preferences -> Content under File Types had been reverted
to defaults for my video settings (I use vlc).

Did others find this happened also?

(Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.12) Gecko/20080208 
Fedora/2.0.0.12-1.fc8 Firefox/2.0.0.12 ID:0000000000 )

It would be better if these settings were retained after an update would it not?