IF the problem persists with a particular "link", even after swapping with known good transmitters and receivers, you could be dealing with RF interference.
The unlicensed 2.4Ghz Spectrum is a crowded and busy space in the RF world. It helps to have a way to "see" what is happening.
I have access to RF spectrum analyzers, but there are cheaper options on the market. See the links below for some help.
Running a wifi network?
Try running-
http://www.metageek.net/products/wi-spy/I'd recommend the Wi-Spy 2.4i. It should enlighten you on what is happening.
On a side note you should install inSSIDer on any laptop on a wifi network. Might help work out network interference issues as well.
http://www.metageek.net/products/inssider/Or it could just be a bad unit... tough to say from the other side of a computer screen.
Good luck! Let us know what you find... I'd like to use this to stream audio to some "legacy" equipment.