Thanks for your reply Palliser!
The Sketch is working but the problem is the same. I also stripped down the sketch from chinophilous and I was focusing on one axis at a time.
Here are some results from your sketch:
ACCEL: 65510 44 244
ACCEL: 65468 10 214
ACCEL: 65406 0 214
ACCEL: 65382 0 184
ACCEL: 65314 65514 138
ACCEL: 65310 65530 172
ACCEL: 65344 42 186
ACCEL: 65434 150 154
ACCEL: 65432 224 150
ACCEL: 65522 216 48
ACCEL: 65512 258 50
ACCEL: 6 240 26
ACCEL: 65510 236 14
It looks like this, even if i don´t move it. Every time the value goes up to 65k the most significant 8 bit part jumps form 0 or 1 to some values around 255.
But I will try to shorten the wires now! I was thinking that 30cm would be ok. But they are probably to long. I will report my results ASAP!
Thanks!
Michael