XP Pro creating A LOT of tmp files on network drive

I have a network consisting of server 2003 with XP Pro clients connected to the domain. The data is all stored on a 2 GB terastation and shared via 3 network shares.

When the users access and modify the files from any program (Word, Excel, Acrobat, AutoCAD….) a ton of files called ‘Copy ## of .tmp’ most of which are of 0kb size. Sometimes there are over 100 of these files and they never go away. Some of them date back to last fall and probably even older.

What could be causing these files to be created and then not get removed? The users can go in and delete them manually but this is not feasible because there are thousands of files in hundreds of folders comprising 20+ GB.