I've just setup a RAID 1 with 2x 500GB seagate and sometimes when i listen to my music that's located on the raid disks the music freezes

could it be the HDDs? or the motherboard raid controller?
it's an ASUS P5B Deluxe that supports raid 0, 1, 10, 5.

I was using winamp.... It occurred 2 times since yesterday....

Thx in advance :D