Pictures on network folders all show up as generic thumbnails

Been searching all over for the solution to this. In Vista, I can open up a
folder on my hard drive and see picture files as thumbnail previews. But if
I open up a network folder, they show up only as generic thumbnails. How can
I get it to always display thumbnails? XP has no problems doing that.

I understand it's that way for network performance reasons. But I have a
fast enough network and I like to keep all my photos on a separate server.

I've already unchecked the "always show icons, not thumbnails" option and
applied that pictures folder template thing.