Files become inaccessible after being moved

Can anyone tell me why a file that works fine where it is becomes suddenly inaccessible upon moving it to another folder on the same partition of the same drive? These files are not specifc--it's ALL types of files, and it is seemingly (to me) completely random when it occurs. Any help would be much appreciated, thanks.

 

Do you have an specific examples? File names and locations To and From?

 

An example would be an mp3 moved from one folder to another on the same partition. Another would be an executable moved from whatever folder it started in (downloaded or extracted too) to any other folder anywhere else on the drive. These files work up until they are moved, and then I can't even delete them.

 

Have you tried scanning for spyware and viruses?

http://forums.majorgeeks.com/announcement.php?f=21

 

Norton and spybot don't pick up anything. I scan regularly. Perhaps there is a better program though; I'm really not sure which ones to trust.