Instruments fade out in mixdown or bounce

[neilbenezra]

Does anyone have a solution to the problem of virtual instruments fading out when you mixdown or bounce a mix?

I've been using Hybrid, Xpand etc and creating subtle underlying tones for film work and find that if I hold down a note for a minute and a half it will play back in the session exactly the same. The problem comes up when I go to bounce or mix down to stereo and the same drone/ tone disappears after about 20 seconds. What is going on and how can this be corrected?

Thanks,
N