tested with svn-04-05-2006--18-04
After some zapping with Timeshift=on MediaPortal cant get a lock on some Channels. This is happening randomly, its not always the same Channel(s).
If you get a black TV MP will display "no signal" in fullscreen. If you deactivate TS the channel is viewed, if you activate TS again TV is black.

h4. Steps to Reproduce
i-loop:
1. Start MediaPortal
2. enter MyTV
3. enable Timesift
4. zap through the channels until you get a black screen
   in fullscreen you will get "no signal" error. MediaPortal.log will show that it couldnt get a lock

!!! no channel changeing from now on!!!

5. turn ts=off -> channel is displayed (Video and Audio)
   MediaPortal.log shows that the channel could be locked
6. turn ts=on -> TV is black ("no signal" in fullscreen)
   MediaPortal.log shows that the channel could NOT be locked
7. turn ts=off -> channel is displayed (Video and Audio)
   MediaPortal.log shows that the channel could be locked
8. turn ts=on -> TV is black ("no signal" in fullscreen)
   MediaPortal.log shows that the channel could NOT be locked
9. close MediaPortal
10. enter MediaPortal
11. enter MyTV
12. the channel that was black befor is now displayed with TS=on
13. after some zapping a other channel is black

ronilse:
 mainly the same issue but he cant turn TS= on, off, on, off infidently like i can.
1. Start MediaPortal
2. enter MyTV
3. enable Timesift
4. zap through the channels until you get a black screen
5. in fullscreen you will get "no signal" error.
!!! no channel changing from now on !!!
6. turn ts=off -> channel is displayed (Video and Audio)
7. turn ts=on -> TV is black
8. turn ts=off -> TV Home GUI freeze
9. Ctrl+Alt+Del to Kill MP & Taskmanager shows a ActiveMovie Window
running as an own process (see picture below).
http://img82.imageshack.us/img82/2265/tvtestblackchannel2jg.jpg

h4. Additional Information
issue also confirmed by bavarian and RoChess