I can't get Launchpad to accept the following bug report due to persistent timeout problems!
Sub-menus and dialogue boxes don't operate properly in Thunderbird immediately after upgrade of Ubuntu from 9.10 to 10.04. This is scary stuff since Thunderbird is close to unusable in this condition! Indeed, I had made a decision to switch to Evolution because this all occurred on my PRODUCTION machine. I tried to report the problem at the time, but Launchpad malfunctioned and trashed my report.
After being told by Ubuntuzilla about upgrades to Firefox, I tried to follow instructions to update both Firefox and Thunderbird. Thunderbird apparently updated successfully to 3.0.4, and so far, that update has apparently resolved my severe problems. However, I am upset that I had to go though the Ubuntuzilla process to fix things!
Note that the 'report a problem' option is missing from Thunderbird, thus I was forced to launch this bug report from Firefox.