Yep, I'm dumbfounded. This has got to be one of the most annoying pieces of electronics I have worked with yet.
I can not get more than a 2 inch range out of these things with a 13 cm antenna. Removing the antenna has a very small impact on performance. It doesn't increase the range, just helps more of the signals get through at the max range of 2 inches!
At this 2 inches, the receiver will pick up the message from the other arduino board somehow with no transmitter plugged in. Although with the transmitter plugged in, it picks up the message a lot more consistently.
I'm almost ready to throw these things in the trash :0
EDIT:
Ok scratch that. Looks like I've got at least one bad receiver. Swapped out the receiver with my 2nd receiver and now I'm receiving messages from one end of the house to the other (about 20 meters). It was missing some signals at that range but it was picking up at least 3 in 5.