hello my friend,
i'm in the same situation with the same program as you!
So i have tried to found solution to this problem many times.
Fistly,if you load a lot of vst,like me(about 10)or you,the song will have prob because music progs cant load many vst and play in a good way.
After researches i found that solution is:or faster cpu or extract to wav the vst channels with more fx!
Also,Dont put many fx in a channel!!
thanx
PS:sorry for the greekenglish!!!