halion sonic problem: stopped notes

I have a very big issue with Halion sonic 1 and now also in Halion Sonic 2, when I play for the first time a note, often it stops after a while. It happens on the first one, not when I’m playing, I would like to know if it’s a problem already known and hopefully how to fix it… I have the same issue with 2 pc (i7 8gb ram) and 3 master keyboard, so I think it’s a software problem. I use Cubase 6 Elements and Hs2 with the newest release.
Here’s a video of the problem:


thank you!