Vista - IMAP spam filtering issue in Windows Mail (Vista 5472)

I've run into an issue with the spam filtering in Windows Mail on Vista
build 5472.

I use IMAP to read email, and my email provider offer a server-side spam
filter, which I've enabled. I had also enabled the Windows Mail spam filter,
until the issue described below occurred.

Today, I received a mail which my server-side filter had judged to be spam,
so it was downloaded to my IMAP spam folder. When I checked this folder, I
noticed the mail, which was not spam, and so, in Windows Mail, I marked it
as not junk. This moved it to my inbox, as expected, but a few seconds
later, it was deleted from my inbox, and is now nowhere to be found!

My wild guess is that the Windows Mail spam filter inspected this mail when
it was moved to the inbox (since it had been downloaded directly to the spam
folder), and then moved it to the spam folder, in which it had already been
marked for deletion from the server, producing some sort of race condition
whereby the delete associated with moving the mail to the inbox was actually
completed after it had been erroneously moved back.

Whatever caused this problem, the end result was that a non-spam mail which
was sent to me has been erroneously deleted from my email server, which is
considerably worse than a spam mail being erroneously left there.

Regards
tas