I noticed this bug on an older version of Recuva and before I posted installed the latest version. Many of the deleted photos I find are marked as unrecoverable... yet display fine in preview... and look fine when recovered. While some files dubbed in excellent condition have obviously been written over... or look like they've been sliced up and reassembled. Even some photos (large mosaics) that I can't get previews for are fine once recovered.
If the file condition indicator can't be trusted...
Best to just restore these files and see how they look in Windows Explorer.?
System is an AMD dual core 5600, Vista 32 premium SP1 with 3 gigs of RAM.