multi tuner plugin troubles

[Nate]

I have two HD Motorola cable boxes. I can control either of them with one of these commands...
channelw.exe 3 123
channelw.exe 4 123
...where 123 is the channel and 3/4 is which box to control. I want Sage to be able to control them. I installed the EXEMultiTunerPlugin and set both video sources to use it. I stopped Sage and set the device_name for the video sources, one to 3 and one to 4. I twice copied StubDevice.ir from Common/RemoteCodes into RemoteCodes/EXEMultiTunerPlugin, naming one 3.ir and one 4.ir. I edited these files to replace StubDevice with 3/4. I set the registry setting to...
C:\Apps\STB\channelw.exe %DEVICE% %CHANNEL%
Sage does not change the channel. Rebooted, nothing. I swapped the device_name, still doesn't work. Rebooted, nothing. If I change the registry to this...
C:\Apps\STB\channelw.exe 4 %CHANNEL%
...then it does work, but obviously only changes one of the tuners. I have Sage running as a service under the LocalSystem user with interact with desktop checked.

I can't figure out why this doesn't work. I've tried everything I could come up with and what I've read in very old threads on this forum. Is EXEMultiTunerPlugin not compatible with Sage 6.3.5.159? How can I debug this further? I tried using a batch file instead of channelw.exe with something like this...
echo %1 %2 > c:\test.txt
...but I couldn't get it to write to the test.txt file. Maybe the way the plugin invokes the registry setting doesn't allow the "pipe to a file" magic to work. I don't know what else to try. I now have 2 tuners and I'm only able to use one.

[MeInMaui]

I use the ExeMultiTuner plugin to control 2 SA3250HD boxes. Check out my guide to see if there is anything in there you might have missed.

Aloha,
Mike