My xbox commands have jumped around.  I tried all the mega lists, hex codes suggested on here, and nothing worked consistently.  It's like the power commands switch when you turn in on/off from the front Power button and the controllers.  My last trick that seemed to work was sending [I think it was] Info then delay, then Power On for power on.  For some reason that worked for like 2 weeks and has never worked again.

If it's toggle bit (like WMC), then why do my DVD transport keys work perfectly?

I'm going to be ripping my gear apart this weekend, so I'll revisit the problem and post if I figure anything out...