Sony Receiver not responding

[msteelefl]

I'm trying to control my Sony STR-DA4ES receiver with the USB-UIRT. I'm using it with Xlobby and I defined the device and learned several commands. However when I transmit the commands, the Sony does not respond. I am able to control my SA cable box, Panasonic DVD player and Audiotron with the USB-UIRT with no problems. I also installed EventGhost just to take the Xlobby variable out of the equation.
I can control the Sony with my Pronto, my cable box remote, as well as a Global Cache GC-100 used with Premise Automation System. I have tried both learning and pasting the Pronto codes into the IR command window, but still nothing. I'm out of ideas on how to get this working.
Any help would be greatly appreciated.

Mark