I have got a serious problem:

I have a KORG X5D synthie connected via Midi-cable with my Computer
(port of the soundcard) As a sequencer software i use Cubasis VST.

Now, if i play a certain time on my Korg (or i let play the
sequencer)...let's say 5 minutes, suddenly, without warning the programs
(sounds) change on my Korg wildly. I mean it's like my Synhie's going
crazy.

This happens in multi and in the normal prog mode. I think midi is to
blame in away and there is some program change thing going on, but i
don't know what to do. I did everything the Korg guys have written in
their manual, but nothing (positive) happened.

Can someone help please!!