Anyone else deployed BrightMail on Exchange 2000 servers

We recently installed BrightMail anti-spam into our Exchange 2000
architecture. It adds a server side rule which moves messages it determines
to be spam to a folder we called "spam" (original I know, customer's
choice)

After this was deployed several users began to get a "Rules in Error" dialog
box which shows
Rule: Server-Requested Client Action
Error: MoveCopy, Unable to create dest. msg.

After that dialog box pops up the header shows on the Outlook Client but the
message can neither be read or deleted.

Any help would be appreciated.

Kassy