Q: cant view icon preview on network volumes

i have the next problem, i can't view icon preview of movies on network volumes, only can view icon preview of something format (codec) nevertheless if i copy the same movie (which I can not see icon preview) to desktop or any local disk folder can view the icon preview, already i enable show icon preview on option of finder and also regenerate the preferences finder but follow without working i desperate, heeelllppp please!!! ON snow leopard and Lion don't have this problem!!  :-(