Bitheadz has released an update for Unity Session. The Unity v3.02 update can be downloaded for free at www.bitheadz.com
After updating, it is recommended that your rebuild the desktop by holding Option-Apple keys while restarting the computer.

This has shown to help many of the problems found in early releases of UnitySession.

If problems still persist, you may want to completely remove Unity, by using Sherlock to find anything that says Unity, and trashing all related items. Then do a fresh install of UnitySession, and immediately perform the UnitySession v3.02 update (before using UnitySession).