transferred files disappear

I just acquired a new Insp6000 laptop for myself and got the chance to finally setup a home network with that and my Dim8200 desktop. I wanted to be able to have all my song files on both my laptop and desktop. so naturally i share my music folder on my desktop and do a copy of them to my laptop.. sounds easy enough?? well after a few hours the files that are added to my new laptop disappear. They still remain on my old PC but have evaporated off my drive on the laptop (like they were never moved to it at all, even disk space goes back to full capacity, no trace of any new files).. So then I go and purchase a crossover cable which works like a charm with XP pro.. however again the files disappear. I tried to place them in different directories with different folder names. All gone!! no matter if i copy 10 or 1000. BUT HERE'S THE KICKER!!! I use musicmatch and it creates a directory for any artist that you rip from a CD. So if i rip an eminem cd, a folder is created labeled EMiNEM. Whatever folder I transfer all my music to those directories stay there (only empty.) WEIRD!!! Pls help. Both systems running XP PRO SP2 with windows firewall, AVG, and MS spyware tool. Yeah I've got them configured exactly alike.