From what I can see from the wire Im going to hazard a guess at what happend.

1) The simple poly shapes were combined and (some of) the vertex were merged where nessecary.

2) The model was then smoothed and rendered, leading to the issuse that have been raised.

3) A couple of us then went on about border edges and merging vertices.

@zabulus did you go back and merge some vertices (that you may have missed first time), while the model was still smoothed?

I'm clutching at straws a bit, but I'm not sure how an already smooth polygon handles merging of vertices - there may be chance that it creates static sharp lines between the edges, instead of the smooth skin like look of the fingers that actually render ok.

This is just me, but I would try and get the model back to a non-smoothed state - a simple blocky polygon - then make sure all the vertices are merged at that point in time.

After all the vertices are merged and you have one solid clean (blocky) polygon model, then smooth the whole thing off and see how it looks.

Its just an idea, but I would give it a go.

Maybe these links might help
Remove a smooth Link 1
Remove a smooth Link 2