This posting is older than 6 months and can contain outdated information.
Thanks for the info. I agree it's unlikely that this is an issue of the Apple Remote control.
Regarding hardware health:
The mere existence of a connection unfortunately doesn't mean anything beyond that there's a USB connection between the IR receiver and the logic board. Since it turns up in the diagnostics, I think it's safe to say that the cable from the receiver to the logic board is connected correctly.
It, however, says nothing about whether all components on the IR receiver are intact and that the IR receiver is positioned correctly (so that its IR sensor receives signals coming in through the small hole on the front of the Mac mini).
You can take a look at how fragile the IR sensor board is, here:
https://www.ifixit.com/Guide/Mac+Mini+Mid+2011+IR+Sensor+Replacement/6412
The analogy isn't perfect, but it may illustrate this well enough: think of an external hard drive. Even if the hard drive itself is broken, it can still show up as a USB device to your Mac. And in fact, the USB connection might work perfectly. The hard drive, of course, will still not work.
That said, another thing you could try is resetting the SMC (which stores USB info IIRC) and NVRAM (which stores settings like volume settings, preferred boot drive, ..):
http://support.apple.com/kb/HT3964
http://support.apple.com/kb/ht1379
Best regards,
Felix Schwarz
