Thanks for coming back to this topic. I thought you abandoned it.
We have received the dump file from Shunsuke Saito and we are currently trying to find from where comes the issue.
At the moment, we think that turning off wintab in the preferences should prevent the bug to happen. It's only a workaround before a fix.
But do you also want to help and record & sent us your own dump file ? That might help.
if so, I will send you some instructions.
Fabrice Debarge, Product Manager, TVPaint Team