Mail: sent/delete errors on IMAP - pls help

[monkeypack]

Hi. I set up two accounts in Microsoft Windows Mail. One is POP and the other is IMAP. POP works fine but I can't delete anything from IMAP (also can't save any Sent mail, but the delete is what's driving me crazy). It's not the issue of having to purge, I know all that. It's that I get an error when I try to delete an email:

SELECTED MSGS COULD NOT BE ADDED TO DESTINATION: UID COPY FAILED, NO SUCH DESTINATION MAILBOX

I think it's trying to put the mail on the remote server (at my job), but isn't there a way I can delete them locally, just to get them out of my Inbox? With my previous email (on Outlook Express on Windows XP) I was able to Delete with no problem.

Any solution? IT folks at work are suggesting I bail on MS Windows Mail and use Thunderbird. Should I do that?

THanks!!!!