Why do you chance messing with Resampling after Voxel Painting? It's like screwing with a mesh after you've spent hours doing UV's and texture painting. There is a reason why you do those AFTER you've finished modeling.
I'm just testing Abn.
I thought this painting was messing things in 3dc. It's not what causes the problem, I think so.
Just merge a cube, ask for autopo with PPP and everything works fine. Clean all rooms, resample the cube, try again and face a possible issue in UVs.
BTW, to resample a vertex-painted object isn't a good idea, indeed.
However, vertex painting is rather a fast way to start and can be helpful when painting on it after baking (PPP)
Edit:
1. Confirming what The Candy-floss Kid reported on the OSX version (under 10.6.8 )
2. Resampling has nothing to do with what I already reported. The bug is random. Just used a ~200k cube and happened again. Depends on the resolution value? How can I check this?