Yes they are cheap IR's, 5 for 1.34, I can't complain...well, I suppose I can a little.
I did hook up the caps and resitors as per blurry ds I found, this happens with the proper parts in place.
I've unhooked them before to see if that could be the problem after reading the adafruit tut that doesn't use the caps and such, the readings were even worse.
These are cheap IR receivers (by price at least ~34 cents). I haven't used them.
According to this datasheet:http://www.hyzt.com/manager/upimg/200987165540.pdf
There are some external - 2x capacitors & 2xresistors required(or suggested) for the IR recevier circuit.
It was hard to read the DS, but it seems to suggest that the modulation frequency is centered on 38kHz, which should be OK. But unlike the earlier post it doesn't give any details on attenuation at other frequencies. (= low quality??)
I also saw a post on another forum, where somebody had left out a resistor when using a FET to drive this particular LED and which resulted in lots of interference. (can't remember details sorry)