Yes, the prob started on 6.04f which was supposedly fixed, but not in any of the zips I downloaded from Infopop & 6.05 is exactly the same even before Beyond Comparing it. Even a clean install of 6.05 has the same problems with the Move Topic & Deleting PM's via the checkboxes. 6.05 even kept throwing up CGI errors when deleting a thread, so I have gone back to 6.04f becuase at least there is one less error to worry about.
Hopefully 6.1 will sort this out once & for all.