lilogre2357, have you made any progress on this? I'm trying to solve the same problem and I am also running mythtv & LIRC. I was unable to get the IR blaster that comes with the Hauppauge PVR-150 to control the DC50X after trying the 700+ known codes. I've submitted a ticket to Hauppauge to see if they can help.

Which IR transceiver are you using? My guess is that you should be able to "teach" your system the codes by using "irrecord".

I email'ed the support folks at Pace and received a very helpful response. In a nuthshell he referenced the XMP protocol and indicated that the IR blaster sold at [Link: usbuirt.com] is compatible with the DC50X. The forums at [Link: usbuirt.com] contain information on getting it to work with mythtv / LIRC. I'm not pursuing this yet as the IR blaster he suggested costs more than I wanted to spend ($50).

Marc