Vista has ben out for a couple of months now, and the problems are starting to mount. The latest issue is a problem with file copying. Quite a few users have reported that they experienced problems with the length of time taken for Vista to complete the deletion of of a file. Microsoft has a hotfix for the issue, but to get it you need to contact Microsoft Support and ask for it.
It’s for reasons such as these, that upgrading to Vista should be left until after Vista Service Pack 1 is released.