cubase 6 export question

hey guys something id like to do that would make my life much easier if when i export and theres some vst synth or sampler to make it mixdown always exactly like it plays within the project. If at some bar i set the start of the loop in the middle of a vst synth midi note, than when i export, it mixdowns out of beat. But if i press play at the start of that loop in the project it doesnt sound out of beat. Is it possible to make it that when i mixdown it sounds like in project always regardless if midi is perfectly lined up at the start of the loop?
thanks

anyone?