Hey Wolfgang,
No, I didn't change anything else. Mind you that I did have conflicts with a Wii Nunchuck library at some point, and it took me a fair amount of time to realise that.
Some good things to do when debugging are:
- set up a test file with nothing in it but the TX/RX code, so as to not cause any conflicts
- try savitch's code he posted in this thread together with a graphing solution, like the Graph example that comes with Arduino - if you look at the receiving end in Processing, you should see steady patterns when you are transmitting - then you'll know that at least your RF links are working - when you stop transmitting you should see a very noisy graph
- put a blinking LED on the receiver side when something is received, rather than debugging to the Serial monitor - that's the most basic and most reliable way to debug - once that works, you can try Serial monitoring
Hmm that's all I can think of for now. You're not in the vicinity of Wellington, NZ are you? Because if so I could possibly give you a hand in person.