Hey. I moved an e-mail-account from one Thunderbird to mine. After that I tryed to move some mails from the inbox to an new created subfolder, but only some mails was moved - the others was lost. Any idea what happend ???

I use/used Thunderbird v2.0 and have experienced similar dataloss. When I move more than one message - usually containing large attachments - from my inbox to a subfolder I lose several of them, which is VERY severe since they work as final documentation to my customers and clients. I have just updated to - version 3.0a1pre (20070530)- but do not know if this have solved this issue yet. please advise.

+1 to the comments above. I´m another victim to data loss after trying to move a mail with a 3+ MB attachment from the Inbox to another folder. It just disappeared! I just started using TB2 yesterday so I have a very small profile. I hope I won´t have to change back to Outlook Express now :(

you're seeing bug 368112 you can wait for 2.0.0.4 to be released, or try a pre-release version from ftp://ftp.mozilla.org/pub/mozilla.org/thunderbird/nightly/latest-mozilla1.8