What's the deal with this?

I was modelling a chicken (something about that phrase sounds funny). Not to complicated, just a cartoony chicken. I made the body and then the wings as seperate objects. Subsurfed everything and it looked great. I decided though that I wanted the wings actually fused to the body with nice smooth edges, so I made it all one object. I had to subdivide some parts of the body to provide vertices to merge with the wings. I attached the wings and then subsurfed and the edges were screwed up. Each corner had a little black triangle and there were several odd looking imperfections. I’ve experienced similar problems before with subsurfs. When deleting part of a mesh and then putting a new section in there, it always leaves these marks on the subsurf, like it’s remembering what it used to be like. Any advice?

Not Quite Entertainment

You need to flip all your normals outside.

Edit mode, all vertices selected, Ctrl_n

And, you have to aviod triangular faces for subsurfacing.

No triangular faces and all nomals outside should almost always give a clean subsurface.