Kossel - all axes calibrated, but height is wrong

Hi,
I'm using a mini kossel with first marlin and now reprap-host. I've got all axes calibrated very good, so any print will come out in the correct length and width - but not height! For example, the 10x10x50mm calibration object is printed 10,0x10,0x62,5.
Or even without printing, just moving: every move horizontally is made correct, every move vertically is wrong. If i let it move from z=0 to z=50, it's 62.5 when i measure it.
If all dimensions would be wrong, i'd say ok, it's the steps/mm. But this way, I've got no idea. Since all movements are interpolated between the axes, i have no idea how this can happen, please give me a hint!

Here some values from my configuration.h, maybe someone with a mini kossel with v-rollers can check if his values are in the same range (first from repetier-host, second marlin):

#define DELTA_DIAGONAL_ROD 228 // mm
#define DELTA_ALPHA_A 210
#define DELTA_ALPHA_B 330
#define DELTA_ALPHA_C 90
#define DELTA_MAX_RADIUS 150
#define DELTA_RADIUS 94.6
#define DELTA_HOME_ON_POWER 0

#define DELTA_DIAGONAL_ROD 228.0
#define DELTA_SMOOTH_ROD_OFFSET 134 
#define DELTA_EFFECTOR_OFFSET 19.9 
#define DELTA_CARRIAGE_OFFSET 19.5

The marlin config is a bit older, the repetier-part might have changed a bit, but it gave similar results.