This may be just another symptom of bug #31186, but will log separately in case it's not. Using mar09 commercial builds, all platforms. You cannot make changes to account settings panels Copies&Folders or Server. I am able to make changes on the main account settings panel upon first launching the dialog, but after accessing the Server or Copies&Folders panel the main panel no longer works to accept input. 1. From mail window, Edit|Account Settings. 2. Click to change html compose setting. This works. 3. Access the Server panel or Copies&Folders panel. Try to make a change. Nothing happens, fields will not change. 4. Go back to main settings panel. Try to change the compose setting again. Nothing happens, now it doesn't work.

it is in fact a dupe. *** This bug has been marked as a duplicate of 31186 ***

Verified as a duplicate.