Unexisting notes played sometimes

Hello,

I’m using Renoise with VST instruments. When editing, saving, replaying over and over again, at some point I can hear an extra tones, that are not in my song. It’s like you play a piano and somebody comes to you and press some key randomly while are you playing. It’s very annoying. After I stop playback, cancel record mode, and play song from the begging it’s gone. After some edits, it’s back again. It looks like a bug. How ever it is long term problem, so I’m wondering if anybody else experiencing the same issue. Could it be any problem with settings vs HW?

Thanks,
Vlastik