Parallels 4 doesn't work on a shared computer

im on a shared imac (running 10.5.6) that recently upgraded to version 4, when the admin account uses Parallels, it works with out a problem, however, when only certain managed accounts try to use it, the .pvm file is shown as having zero KB, everyone has full permission, and this is only on three of the 5 users. On the admin account and the one managed account it works on it shows as nearly 11 GB. Any ideas on why/ how to fix?

 

http://kb.parallels.com/en/5733