Certain video decoders are prone to this, in particular the latest version of Intervideo decoder. Try a different video decoder.
[SIZE="1"]AMD Athlon X2 4200+ CPU, Gigabyte GA-MA770-DS3 mobo, 2GB RAM, 1TB SATA HDD, DigitalNow Dual Hybrid PCIE S2 and Hauppauge HVR2200 capture, ATI HD4670 video with HDMI-HDMI to 32" LCD TV at 1360x768, Win7 Home Premium 64bit, GBPVR 1.4.7, EVR renderer[/SIZE]