I myself have had no problems with InTeen since patching other than a lack of new homeless kittens coming into the shelter for adoption - unless it's inTeen that is somehow causing my sims to graduate and not get diplomas but I highly doubt it.
Actually, as of the second NL patch, InTeen is causing your sims not to receive a diploma. An update to the InTeenimater was posted to the website a couple weeks ago and corrects this problem.