I'm experiencing freezes with presentation while displaying PowerPoint in full screen.

The laptop/PC still functions and the connection to ScreenBeam will remain active. This issue may occur on Windows 7 or 8 systems using the AMD Catalyst software-switchable graphic utility set to "High Performance" mode. 

Workaround - Disconnect the current ScreenBeam connection and wait for 30 seconds. From your Laptop/PC, re-connect to ScreenBeam Receiver. When "Switchable Graphics" window appears, close the window or select "Power Saving" mode.