I have one of those; it works flawlessly. Have you been able to determine exactly where the IR receiver is on that box? I'm trying to add it to my IR repeater without a lot of luck.
You aren't kidding, it is hard to find! I did a lot of playing around by selectively blocking the front panel. The IR receiver is really, really sensitive! (either that or the transmitter is capable of giving sunburns.
From my selective blocking, it appears that the IR receiver is just to the right of the 2nd input LED (it might be exactly between the 2nd and 3rd LED, but I can't be that precise. That's more of a cosmetic guess. The one thing that's clear is it is to the right of the 2nd input LED and to the left of the 3rd.