>I'm trying to "learn" the codes of various IR remotes.  I've
 >found that the pulse widths from the remotes vary by as much as
 >30% depending on distance.  I'd appreciate at suggestions,
 >specifications, etc.  that anyone can give me regarding
 >the remote formats.

Are you using an integrated IR receiver module?  I was _very_
surprised to find that Sharp, Temic, and possibly others have
a published output pulse width tolerance of plus/minus 33%

Perhaps one could achieve a tighter tolerance by building a brute-
force photodetector using just a low-sensitivity IR diode.  I
think that's what a lot of learning remotes use.

You could also try to build your own sensitive detector with
a Philips TDA3047.  I tried one a couple years ago, and got
pretty good results.