Norton Anti-Spam uses random folders

Hi,
a client of mine has a weird problem between Norton Anti-Spam and Outlook Express 6.

Norton Anti-Spam created its Mail Rule to move all marked spam into a specific folder.

Problem: It doesn’t happen. Not only does regular email appear in the spam folder and vice versa, but sometimes new emails appears in completely different folders. There is no other Mail Rule.

Any ideas?
Thanks!