Titlebar MiniIcon glitch with nouveau

After moving from nvidia-drivers to kms/nouveau, fvwm titlebar icons (MiniIcon) look very bad:
gentoo-sources-36, xorg-server 1.7 and 1.9, GeForce 4 MX 4000
Do you know anything about this?

Absolutely nothing to do with FVWM. That much I do know.

– Thomas Adam

I know, with the proprietary driver it’s all fine, but I thought somebody might have the same issue.

It doesn’t matter who else has the same issue – it’s not appropriate here.

Would you walk into a fishmongers to ask about help with a vacuum cleaner? No. You go somewhere more appropriate. The only difference is, I’m telling you that this isn’t a generic “something somewhere is wrong with my machine, and just because I happen to use FVWM, I’ll ask here anyway” forum.

– Thomas Adam