[mythtv-users] Stuck on Channel 4

[DCL]

I have 2 prv-250 and 1 pvr-350 cards installed in my mythtv system.  I 
am now in the testing phase.  After installing all the required software 
everything seemed to be working alright.  Then the other day two of my 
pvr cards got stuck on channel 4.  When I recorded other channels,  all 
I got was channel 4.  Now my third card is also stuck on channel 4 
also.  Even while viewing live TV the remote will not change the channel.

Has any one seen this before?

 How can I force the channel to change manually?

Are there any setting I should check?

Could there be a problem with the Mythtv application?

Thanks Dan