dropped frames with HD (x264 mkv) files when enabling EVR

[kkendall]

MediaPortal Version: MP/TVserver 1 RC2
MediaPortal Skin: BlueTwo
Windows Version: Vista
CPU Type: Intel Core 2 Duo E6750 775 1333FSB 2.66Ghz 4MB
HDD: 2x Samsung spinpoint 500GB
Memory: 2x Kingston DDR2 ValueRAM 1GB 667 CL5.0
Motherboard: Asus P5K
Video Card: NVIDIA 9600
[Sound Card AC3: AC3 and DTS: S/PDIF
1. TV Card: FloppyDTV
1. TV Card Type: DVB-C
2. TV Card: Hauppauge PVR500
2. TV Card Type: analog
Satelite/CableTV Provider: CAIW
HTPC Case: Silverstone LC17b
Power Supply: ANTEC
Remote: Microsoft MCE 2005 remote
TV: Philips
TV - HTPC Connection: Composite

Hi, I got problems with x264 playback. When I use VMR9, every frame of my 720P/24 plays perfectly on 24 fps. But the color isn't quite perfect with VMR9.

The color is perfect with EVR enabled, but now I get dropped frames with 720p/24 x264 mkv movies... I have hw acc enabled for x264 and as you can see my pc should have no problem at all with heavy codec processing. And that is the weird thing. VMR9 works perfectly, but once EVR is enabled you can see judder/dropped frames when hitting Ctrl + 1.

HD tv on 720p/50 in MPEG2 runs as smooth as silk with EVR enabled.
Anyone with the same problem? OR does anyone have some tips, hints or solutions?

ps. I also have trouble with missing audio when changing channels. You have to stop tv and start it again to have the audio back, but that is something else...(I see a lot of people having audio problems with tv watching lately...)