Upgrade to the latest hotfix (2675) and also make sure you have the latest video card drivers.
I have seen this and it seems to be memory related - i.e too many other programs running.
Someting else to look at is do you have the trace and reference on in the background.Try turning this off.\
I does cause problems with the info box when you have something selected - it won't show any properties for the selection.
Turning the trace off fixes that.
Maybe it is related?
Barry.
One of the forum moderators.
Versions 6.5 to 27
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11