Comping is new to me, and its a pain to be familiar with.

In X1 i could record lets say 8 bars of piano and save it.
when i wanted to continue to record i could always hear the miditrack ( piano playing )
in record mode and had a reference how i played.

But now in X3 when i want to continue to record, i cant hear the recording
of the previous take, its all silent ..., how can i hear the midi playing when i continue to record
on the same track further. 

Change recording mode to "Sound on Sound".

Duhhhh, so mutch easier in X1 ...., now i need to change between " modes "
of recording ..


thanks anyway, ill try that.

it worked,  thanks

So as i understand it, ( sound on sound ) is the orgignal way of recording then ?

No. It's just one of several record modes you can set.