1. Emitters and Sensors prefereably should be matched in the same IR range... One Emitter may not work well with a Detector best suited for a different range.

2. You may be being swamped by ambient light (which contains IR, UV, cats, dogs and the neighbours barbie smoke as well). To see if this is the case, try your experiment in a darkened room and you'll discover you have a much improved range over a room in broad daylight. Use an IR filter (wrench one out of your neighbours TV's facia as an experiment). Modulating the emitter at something like 32kHz and decoding similarly by the detector is what separates the signal from ambient noise (this nothing to do with actually sending Data).

3. The TSOP range of Detectors (eg TSOP17xx & TSOP18xx) contain integral filters and decoders which means you don't have to worry about that part of it. Even then when you look at the Datasheets you'll see they are optomised for certain frequencies).

4. You may notice (from Datasheets) that the junk IR Emitter/Receiver pairs are really specified for only a few cm operation.