If I turn off time-shifting I can watch TV (all channels).
Definately turn off timeshifting and try tuning a channel. If this works reinstall MC as Administartor (Right-click Run as Administrator), re-enable timeshifting and see if it still crashes.
When I start MC as Administrator and reenable timeshifting, MC does not crash but audio loops and following is shown on the screen: "Playback graph ERROR: - EC_ERRORABORT Code 80004005. Restaring Player".
Then I have to kill the process because MC hangs.
2) Under "Tools --> Options --> Video" select JTV and have a play with various filters (I like Auto for Source, FFDSHOW for Video and Audio, Haali for the Video Renderer)
I played with the filtersettings and found out that the reason for the timeshift-problem is the Microsoft DTV-DVD Video Decoder which is used for MPEG2-Playback (default under Windows 7). When I use ffdShow and EVR or Halli Renderer everything works, but the picture is interlaced.
I can enable "Deinterlace" in ffdShow then my picture is correct, but then ffdshow deinterlaces all my videos which I play with ffdshow. Under Tools -> Options TV -> <My device> -> Advanced Properties there is an entry "deinterlace" but it seems not to work.