I'ts supposed to have a delay compensation but maybe there might be some issues with VSTi's
maybe in preferences> VST page ?¿
quote regarding vsti :you'll find a Delay Compensation Threshold setting. This is where you can tell Cubase SX to keep plugins with a certain delay threshold to be affected by the Constrain Delay Compensation function, which means they'll probably be disabled while you are recording with the virtual instrument.
In a nutshell, by engaging Constrain Delay Compensation when trying to record a VSTi, you're telling Cubase SX to take it easy compensating for delays caused by plugins, and to tighten up the timing as best it can until you've finished recording your part. Then after you've completed your recording, you disable Constrain Delay Compensation to return to normal mode.