Subsurf made a hole in my object?

[Deu3]

My 350 vert hand has a little trouble when I add a subsurf modifier. I've tried subdividing the area before I add it and even moving the verts out further apart from eachother but everytime i add the subsurf I get a nice big hole in the middle there.

Blender 2.69

Any sugestions? :D

 (Edit: I found a fix kinda...If I add an edge split modifier before the subsurf I can turn the split angle up 180degrees and it fills in the hole magically)

[Gaia Clary]

Check if you have hidden faces or hidden edges in the "inside" of the hand. In edit Mode: Select -> Non manifold

[Deu3]

Theres not even any verts in there once the subsurf is applied. its like someone poked everything out of that area. A blender ghost.

 

Heres another strange thing, I thought maybe the normals might be flipped (even though theres no faces there in the first place lol) so I ctrl+N and blender crashes to desktop, over and over. Could this be related? I might need to reinstall...

 

EDIT: No change after reinstall (Cleared all settings and plugins)

[Drongle McMahon]

This sort of thing does happen if you have split edges when you apply subsurf - that is a sequence of edges where the vertices attached to either side of them are actually two separate vertices. The superimposed vertices get pulled apart by the subsurf. It can happen in variou ways without applying the edge split modifier, such as explicitly splitting the edsges, separating and rejoining etc. You can check by selecting the relevant vertices in vertex view mode and seeing if the count is what it should be. If the duplicated vertices are near enough or exactly superimposed, you can merge them with Remove doubles, providing the normals are matched up (Ithink that's required - not certain).