Thunderbird hangs

I am seeing two issues that I cannot explain and am wondering if anyone else is experiencing them or has a solution..

Item 1: Thunderbird running on XP.. from time to time, the user will select an email and tell it to delete (right click del, or hit the del key or hit the del button). Thunderbird will hang and be unresponsive for about thirty seconds. Then the email will delete and everything appears hunky dory.

Item 2: Thunderbird on W2k.. I have a local mail file that collects the junk (junk). When I select the folder, Thunderbird pegs out the processor and hangs. I can release the computer by ending thunderbird in the task manager, but I can’t delete the junk out of that folder because it hangs whenever I touch the folder. This does not happen on any other folder.

TIA..
David