Hi Yenmonger, thanks for posting the model.

Directionally it all seems to be ok, I think it may be having some difficulty with the coincident surfaces in here.

One thing I noticed is that it looks like it is supposed to be symmetrical, but there are some differences in that problem area from the other side.

On the "good" finished side, there is a pocket in this area:



But on the problem side, there is not the same kind of pocket:



And if I view it from the back side and zoom in:





There is a pretty thin little slivered surface there, that is not likely to be helping things out very much.

If everything is built to a pretty tight tolerance maybe it will be easiest to delete those faces along that side and mirror all the good ones over if they fit properly, I will give that a try here.

- Michael