RF with MSP430 and CC1111 - Strange behaviour

Hey Folks,

I wrote a MSP430 program that receives and transmits data in a fixed 
lenght format via RF. Everything there works fine: If I use one MSP to 
send data, another MSP, who is programmed to receive packets, receives 
them.

Now I wanted to use a CC1111-Dongle to send packets and one MSP to 
receive them.

But now the things start to become strange:
I send exactly the same packets via RF, but the receiving MSP only 
receives the packets sent via the MSP and not the one from the CC1111.
You may ask how I'm shure, that the packets are exactly the same: I 
checked it with another CC1111 and TI's Packet Sniffer and the sniffed 
packets there look exactly the same (except for LQI and RSSI which 
differ a little bit, but I think this is normal).

I'm new to the field of RF-transmissions and have no idea, where the 
problem could be. I'm hoping that maybe one of you can give me a hint, 
where to look for errors? Maybe one of you already had the same 
problems?

Thanks in advance,
erdi