Hi Nico, no I'm not familiar with that problem, this is the first I've heard of it.

Something like that affecting the entire OS pretty much indicates some problem with the video driver though.

One thing you might try to see if it helps is to install the latest XQuartz from here: https://www.xquartz.org/ and then change the setting in MoI for it to use the system installed XQuartz rather than the bundled one as described here: http://moi3d.com/forum/index.php?webtag=MOI&msg=6967.4

MoI v4 may behave better on your system, for v4 I've done a significant rewrite to make a native compiled build for the Mac, it no longer uses Wineskin or XQuartz at all. I'm expecting to release v4 by the end of this year, the beta version is available to existing customers here: http://moi3d.com/beta.htm .

- Michael