when I render a beat in renoise and loads it into cubase or live It will not loop right, so I took a look at the samples and found out the renoise adds some empty data in the beginning making the sample longer than one I render in cubase/live, why is that, is ther anyy thing I can do. This also happens when I render to sample inside renoise, renoise always adds som ms in lenght and stops the groove 
This is because of the lack of the PDC. Check other threads about it.
You either avoid plugins which add latency, or manually edit the loop later to make it match the beat.
Renoise has some tools to see if the sample is in the tempo. (Sample editor ruler and snap to beat).
Ok, but there are no effects on my new beat in renoise and still I get this extra length, and the samples that are used in the song are cut right to the wave. this dont make sence…
does a bypassed effect in the mixer create delay ?
yeah, it’d be cool if renoise automatically deleted the rendered in silence.
weird - this only happens to me with a couple of plug ins.