[mythtv] Live TV fails

[jam]

Hi
before I go spelunking, trash the database etc maybe someone can say aaah

I upgraded to svn 21634
One (only) frontend cannot watch live TV, all are OK with recordings

The backend log says many times:
2009-09-03 08:59:15.375 MythSocket(7fc2f00d5630:-1): writeStringList: Error, 
called with unconnected socket.
and
JumpToProgram's OpenFile failed
not much else, and nothing that looks interesting.

The frontend pops a dialog that says:
error opening jump program file buffer

Thanks
James