More news: I was searching MS web-site, and came across a forum dedicated to Windows Media Center Edition called "the greenbutton". Evidently, Microsoft had a forgiving IR receiver in the original MCE, but went to requiring toggle mode in MCE 2004.

[Link: thegreenbutton.infopop.cc]

is a link that claims that if I follow these directions, the PC will no longer require toggled signals. Others have said they tried it and it works. I'll let everyone know the outcome tonight...