There are 4 i/r receivers supported in lmce, the first 3 are 'native', meaning the manufacturers provided binary drivers that are linked into lmce. 1) USB UIRT, which I use and works flawlessly. You don't even need to pause the movie to plug one in, it just works out of the box. 2) Tira and 3) IRTrans, which also are pnp and work out of the box, and I'm told work well. And 4) anything that LIRC supports, which includes some of the wmce i/r receivers, though not all, and is mostly reverse engineered stuff. In practice I've found some of the wmce i/r receivers are pnp. Plug them in and lirc is automatically installed and the receiver starts working.
However, for some reason, the accuracy of the i/r reception on the wmce+lirc is not nearly as good as the usb uirt, or as the wmce receiver under windows. I know the wmce receiver *can* do a good job because it works well under Windows, and I'm not sure why LIRC isn't so accurate. It's my understanding that the reason this may be the case is that the 3 i/r receivers lmce supports natively (ie w/out using lirc) have their own circuitry in them to do the i/r decoding and spit out a clean hex code. Whereas with the wmce receiver, to keep costs down, is a really 'dumb' device and all the logic is in the software, and Windows software does a better job of translating the pulses into i/r codes than lirc.