Long story: I'm on a 2009 15" Macbook Pro Intel Core 2 Duo running OS X 10.6.8. A couple weeks ago, I suddenly began having problems with certain features in Gmail... but only in Firefox. Specifically, I was no longer able to preview attachments in Gmail's new attachment viewer. After a long back-and-forth on the Gmail forum with no results, I turned to Firefox. After poking around in Firefox Help, I decided to reset Firefox. This solved the issue with Gmail, but in turn created two new and more serious problems with Firefox: (1) I am unable to save my History settings in the Privacy tab of Preferences (I want to use Custom settings; every time I choose this option from the dropdown menu and close Prefs., as soon as I open Prefs again, the History setting is back on the default "Remember history"; (2) Even more grave, and evidently related: every time I quit Firefox, all my tabs and tab groups are gone upon re-opening. I can restore the previous session, but this is obviously not the desired solution. I've essentially tried everything suggested in the designated articles in Firefox help, from resetting Firefox again, to trashing the prefs.js file in my Profile folder (I don't have any other pref files--i.e. no "prefs-n.js or "prefs.js.moztmp" or "Invalidprefs.js"... I also don't see a user.js file in my Profile folder either). I've even used Disk Utility to repair permissions on my Mac HD... for whatever that's worth. I'm so sick of all this that I'm seriously considering ditching Firefox altogether. Can anyone out there help me figure out what's going on? Accidemic13