Steve,

Just had the same issue after buying a new KDL52XBR4. Great TV but lousy tech support when I called about remote discrete codes. In fact, even their Level 2 person I spoke with did not even know what a discrete code was! But was able to find them here on this forum at [Link: remotecentral.com]
I have installed and tested them on my Pronto 6000 and all work great.