VST System Link

Hi,

I’ve got a problem with the VST system link - the good news is that the connection has been established but there is a midi glitch/problem wherby a snippet of a song say a two bar phrase that is looped and playing back -Once its looped around x times (say half a dozen-ish) Cubase becomes erratic and jumps all over the place…

Cubase Elements 6 and Cubase 6.5 are being used for this…thanks…