That really sucks D;
It does seem that way, but who knows.
Maybe it's something that can be fixed very easily
...
eventually xDD
I finally fixed it.  I hope it can work for you.  It actually turned out to be a simple solution for me.  Anyway, I took the advice of what the people said on here and it worked.  I went to Graphics/Performance Options and changed Sim Object Detail to High.  I made other changes in there but it didn't effect the way the sims faces looked.  Anyway, when I went back to the houses that were messed up, the faces were the way it was supposed to be.  Here's a picture of what you should try and change.  Good luck!!!