Issues Found on XPS 710 using ATI X1950 XTX cards and driver version Catalyst 7.2:
 
Cannot enable clone mode when using a TV as the second monitor.  
Can only get clone mode to work when both monitors are attached to the primary graphics card.  

Since the TV output is on the secondary card we can only enable the TV in extended Desktop mode.  
The CCC shows the TV as being in clone mode.  It is not.