I have created an assembly with a flange that uses clamps.  I have pulled 4 clamps in from Content Central and was able to create tangent mates for two of them, but the other two don't seem to work properly.  I can select the same component elements, apply the same tangent mate, but the behavior obtained is completely different and unexpected.  In the screen shot below, the Tangent 10 mate the problem mate.  The Tangent 5 and 6 mates were made the same way and turned out ok.