Sometimes when closing the TV channel preview window, TsReader.ax can cause a crash. Reported by Sebastiii in conversation thread.

h4. Steps to Reproduce
Preview a channel then close it - it can crash randomly.

h4. Additional Information
Issue appears to be caused by timeshift buffer files being immediately deleted as soon as play is stopped - the TsReader.ax file duration update thread can still be trying to read the files so it can't be cleanly closed, and is then forcibly terminated (which tends to cause the crash).

Solution is to make sure duration thread has been safely paused before allowing 'Stop' method to return (using a thread lock). Tested in 'TsReader_noStopMod70' dev version - http://forum.team-mediaportal.com/threads/experimental-tsreader-development.102693/#post-811296 - no problems reported so far with the mod.