Tuning Channels on DirecTV via Serial Cable

[albie]

I have a Sony SAT-B55 receiver connected via serial cable to my PC. I've noticed that when changing to a channel greater than 200 via SnapStream, the receiver doesn't change the channel. It just stays on the channel you are currently on. SnapStream shows that I've changed the channel (via the on-screen display), but the channel is the same.

If I change channels using the IR remote that comes with the receiver, it works flawlessly.

I did some testing with the DirecTV control software from pcmx.net and found that there are two different command sets that can be sent to the receiver. One is for signaling from a serial cable, the other is for a remote.

With the DirecTV control software, I can successfully change channels by entering in commands (in hexadecimal format), that correspond to the commands for the remote, not the serial cable. If I enter serial cable commands, I get failure notifications back from the receiver.

My questions are:

1) Does SnapStream use the serial cable command set as opposed to the remote? If so, is there a way to change this?

2) Does SnapStream use its own proprietary controlling software to tune channels on directv receivers? or have they licensed the software from someone like pcmx.net?

3) Would it be better for me to just scrap the serial cable connection and get an IR blaster? I've read posts that say that they are slow and difficult to configure.

System:

SnapStream 3.4.4
P4 2.5gz, 512MB RAM
160GB HD