Mpeg Thumbnails in XP

[noblues]

I used to get thumbnail's for Mpeg type files in XP folders, but after having RealPlayer changed my file assignments (I've now changed them back to assigned to Media Player V9) I find they only display as Mpeg icons, despite selecting 'view/thumbnails' ....

Any clues ?

(PS : Video Clip format files do display as thumbnails OK).

Thanks