I migrated from latest subversion of Firefox 3.6 to 11 on MacOSX. I migrated with the profile in place and backed up separately, just in case. File permissions.sqlite in the profile remained the same but the cookie exception list was empty after upgrade. Attempt to add sites to "new" empty exception list failed as sites/permissions would disappear on Firefox restart. Attempt to copy (identical) permissions.sqlite file from the backup into the profile yields temporary success (sites appear in first Firefox start after that). However on Firefox restart list again disappears from the "exceptions" (which is again empty) while there is no change to the permissions.sqlite file, it remains there with full content. Attempted variations on the theme by erasing and setting completely new profile, adding old permissions.sqlite into it - same results. Examined empty permissions.sqlite of newly created profile with old one. I do not know SQLite but opening lines of the files (defining database I assume) have some fields that are mismatched - is different version maybe the culprit (I hope not)?... Any suggestions? (I would really hate to re-enter the exceptions list which contains years/thousands upon thousands of items by hand, but even that may not work - as I said new sites disappear on restart).