Now crashes as soon as I try to select a channel

There is not much we can see in the logs.. only:

Code (text):

2012-04-27 21:16:15.370505 [Info.][MPMain(1)]: Using alternate configuration file: C:\Users\Mark\AppData\Local\Temp\MPTemp\MediaPortalTemp.xml
2012-04-27 21:16:15.382505 [Info.][MPMain(1)]: Main: Starting MPWatchDog
2012-04-27 21:16:15.437509 [Info.][MPMain(1)]: Main: MediaPortal v1.2.3.0 is starting up on Windows 7 ( Service Pack 1 ) [6.1.7601.65536]
2012-04-27 21:16:15.437509 [Info.][MPMain(1)]: Build: 1.2.3.0
2012-04-27 21:16:15.440509 [Info.][MPMain(1)]: Main: Last install from WindowsUpdate is dated 2012-04-27 09:26:12
2012-04-27 21:16:15.441509 [Debug][MPMain(1)]: Disabling process window ghosting
2012-04-27 21:16:15.441509 [Info.][MPMain(1)]: Main: Using Directories:
2012-04-27 21:16:15.442509 [Info.][MPMain(1)]: Base - C:\Program Files (x86)\Team MediaPortal\MediaPortal
2012-04-27 21:16:15.442509 [Info.][MPMain(1)]: Log - C:\ProgramData\Team MediaPortal\MediaPortal\Log
2012-04-27 21:16:15.442509 [Info.][MPMain(1)]: Skin - C:\ProgramData\Team MediaPortal\MediaPortal\Skin
2012-04-27 21:16:15.443509 [Info.][MPMain(1)]: Language - C:\ProgramData\Team MediaPortal\MediaPortal\Language
2012-04-27 21:16:15.443509 [Info.][MPMain(1)]: Database - C:\ProgramData\Team MediaPortal\MediaPortal\Database
2012-04-27 21:16:15.443509 [Info.][MPMain(1)]: Plugins - C:\Program Files (x86)\Team MediaPortal\MediaPortal\Plugins
2012-04-27 21:16:15.443509 [Info.][MPMain(1)]: Thumbs - C:\ProgramData\Team MediaPortal\MediaPortal\Thumbs
2012-04-27 21:16:15.444509 [Info.][MPMain(1)]: Cache - C:\ProgramData\Team MediaPortal\MediaPortal\Cache
2012-04-27 21:16:15.444509 [Info.][MPMain(1)]: Weather - C:\ProgramData\Team MediaPortal\MediaPortal\skin\DefaultWide\Media\Weather
2012-04-27 21:16:15.444509 [Info.][MPMain(1)]: Config - C:\ProgramData\Team MediaPortal\MediaPortal
2012-04-27 21:16:15.444509 [Info.][MPMain(1)]: Main: Assembly creation time: 10/04/2012 3:16:46 PM (UTC)
2012-04-27 21:16:15.446509 [Warn.][MPMain(1)]: Main: MediaPortal is already running

But maybe your TV Database is crashed? You can try and repair it with:

Hi,
From your application log it seems to be some memory leak, can you list up what system you use exactly?
& please reboot computer & try to start watching tv after that, when it crashes grab logs & attach to you're post here .

Regards
Roy