trouble with midi sync

hi people i'm in need of some help because i'm forever trying to get the gear working and not even getting to the point of making any music

i am trying to play loops on ableton live4 and use a korg electribe drum machine as well, syncronising them by midi clock i.e. press play on the computer and the electribe plays also, cycling its pattern

and its almost right but the beats wander away from each other, usually at the start of every 2 bars. the best way to describe it is like when your mixing vinyl and one record is too slow and drifts off, so you start to hear the drums going duh-duh

ive tryed two soundcards and the same thing happens, right now we are using m audio 10 10lt . the computer is pretty old, an amd duron 900mhz, but im not pushing it, this problem happens even when theres only one loop playing and the cpu meters only at say 2 %