Strange error message

I have set up a serial robot (Mitsubishi RM-501) with 5 rotation joints. With the new joints-axes patch i have joints 0-4 and for axes the X,Y,Z (cartesian) and A,B which i still try to understand what they express and the mathematics behind it. Homing works just fine and jogging from X 95 to X 105 (with Y set to 0 and Z set to -160). But when i am in X 95 and use G1 X105 Y0 Z-160 i get two errors:
1) Linear move on line 0 would exceed C's negative limit
2) invalid params in linear command

seams your limits of the ROTATION does not support to move to that coordinate

But which rotation and how were those limits set?