Sorry that this got missed. I've just moved it to the technical forum for you.
I'm not able to reproduce this behaviour here on my test machines so far, but if it's not too much trouble, could you send am email to firstname.lastname@example.org with as precise steps as possible to reproduce the problem, e.g. starting with a blank canvas, using a specific tool at specific settings and what you need to do to observe the problem?
Also, if you could send the general specs of your machines that would be helpful. Reproducing it with the mouse seems a good first step.
If I don't see it here we can look at what the differences are between our setups to hopefully come to an understanding of why this is happening for you.