Probs with AVI files

Just purchased my mini today, already owning the HD version.  Have a series of AVI (XVID codec) files, all show up in the preview window, but on selection only about half of them will play - get message saying format not supported.  Anyone any ideas


Just ran 2 files through GSpot - the only difference is that the playable file is XViD 1.2SMP which is “Open DML (AVI Ver 2)” and the non playable is XViD 1.1.2 Final  which is  " DivX Style “packed bitstream” AVI, (AVI Ver 1)