thumbnails change by themselves

hi
im running windows xp s/pack 2
my problem is that i store my music and picture files on another h/d (f)
and for some reason recently the thumbnails ie album art seem to change on there own at random,,,,,ie i have a file titled george harrison with a pic of him in it,,,,,and when i opened my music files today it had a thumbnail of simon and garfunkle,,,,,,this has been happening for a few months now and it is doing my head in,,,,,,,,,,it also appears to happen with other thumbnails on my pc,,,,hard to keep track of but its definatly happening with my picture files as well

any help on this very annoying problem would be appreciated

i have run virus and spywear programmes and as i said these files are stored on a seperate internal drive,,,,,,,,i have 28 gb of music files alone stored and im getting really fed up with keep changing the thumbnails back

help me,,,,,,,,,,please

many thanks

gav