Hi PaQ - that will happen in some situations (incomplete fillet result still returned) but not others. I'm not really sure right now if I have much control over that part of filleting, but I can look into it in the future. For now I have made a note in the wishlist for this (http://moi3d.com/wiki/Wishlist).

Can you please post or send to me the model file so I can have that for testing?

I do have an updated geometry library that has quite a few fixes to fillets, that is the last thing that I am going to incorporate into the first v2 beta. So we'll see if that helps things out, I think it incorporates an additional fillet corner type.

- Michael