1. Update "January 2006 Update Rollup for Windows XP Media Center Edition 2005"
http://support.microsoft.com/kb/912067/en-us
2. Country Setting in Media Center ? "China" ?
3. You did not specified the MPEG-2 decoder for Media Center.
Use the Windows XP Video Decoder Checkup Utility's "Set as preferred" button to set the MPEG-2 decoder for Media Center.