endstop problem marlin (no replies)

Hi,
I got a problem with the endstops using marlin+minitronics board;

everytime I home one of the axis it does react to the home switches but it travels some extra distance beyond the home postion resulting in the axis bumping onto the heated bed etc before it stops..I'm used to using sprinter with sanguinolulu without any problems...
Maybe someoneknows how to fix this..

Thank you!