[PA_Willy]

I have seen these effects too.

Sometime ago, I discovered that one of the possible causes is the VSync. If VSync is off, then there is a higher possibility to see this result.

Test it. Switch on VSync and Triple Buffering on your driver panel control and see the tracks. Later, switch off and compare.

But this is not the only reason. I have felt this in several tracks although the VSync was on.

Regards.