I am definitely sure, Mikev.
I have set up completely new Scalix installations to test this, so there were no imap processes running at all, except for the root one that is always running. After killing the user's processes, I checked again with ps aux | grep imap. Again, no imap processes were left at all.
Did you test this on your system and didn't get the error?
[EDIT]
I have now created a small video file that outlines what I'm doing and what the problem is. The size is only 8.4MB and it's only 4 minutes long, so please do take a look. I apologize for not having a better file host at the moment.
http://www.megaupload.com/?d=OD8IIBL2