Problem: Running Boxee in full screen mode on secondary monitor causes CPU to spike 100% and system to lag.
This is a reproduceable problem for me. If I run windowed or on the primary screen I don't experience these problems.
ATI HD4670 (dual DVI output)
ATI Catalyst driver 8.690.0.0
Winvnc (UltraVNC) video hook driver
2* 1600x1200 LCD monitors