MKV plays smoothly in MPC Classic BUT NO in MP (1 Viewer)

[pjandreu]

MediaPortal Version: 1.2.0 Alpha
MediaPortal Skin: StreamedMP
Windows Version: Windows 7 Ultimate 64
CPU Type: AMD Athlon 4850e
HDD: SAMSUNG HD322HJ 300Gb
Memory: 4Gb Musking PC2-6400
Motherboard: Gygabyte GA-MA78GM-DS2H
Video Card: Integrated ATI Radeon HD3200
Video Card Driver: Catalyst 10.10
Sound Card: Integrated Realtek High Definition
Sound Card AC3: no AC3
Sound Card Driver: Realtek 6.0.1.6167
1. TV Card: Cinergy C PCI
1. TV Card Type: DVB-C
1. TV Card Driver: 1.1.2.401
2. TV Card: TechniSat DVB-PC TV Star PCI (BDA)
2. TV Card Type: DVB-C
2. TV Card Driver: 6.1.7600.16385
3. TV Card:
3. TV Card Type:
3. TV Card Driver:
4. TV Card:
4. TV Card Type:
4. TV Card Driver:
MPEG2 Video Codec: MPC-MPEG2 Video Decoder (Gabest)
MPEG2 Audio Codec: MPC-MPA Decoder Filter
h.264 Video Codec: MPC-Video Decoder
Satelite/CableTV Provider:
HTPC Case: Nox Live Imon
Cooling:
Power Supply:
Remote: Conceptronic CLLRCMCE
TV: Samsung 46B6000
TV - HTPC Connection: DVI

Hi all.

I've a problem playing 50fps MKV files I build from Full HD Videocamera. I can play them without problems with MP Classic, but the same file, played in MediaPortal, flicks like hell. I use Shift+1 key combination to see play info, and I realized that it is playing no more than 29fps, and dropping frames continuosly. It's strange, because I use MPC-Video Decoder installed with MP Classic to play High Definition MKV's.

Briefing: MKV's with 25fps or 30fps OK, MKV's with framerate higher than 30fps doesn't play smooth.

Does anybody know what can be happening???

Thanks in advance.