When creating new files or trying to open existing ones, entities will not display on model or sheet space unless they are highlighted. All functions operate like normal but as soon as the focus is removed from the entity, it disappears. The problem just happened the last 2 times I tried to use the software and I am not aware of any major changes to my system that could have caused it.

Does anyone have any ideas what is causing this issue?

NOTE: changing line colors, background color, and updating the video driver has not solved the issue. Running V1R4x64 on a Windows 7 Enterprise 64bit.

EXAMPLE: Two circles can be seen when highlighted but disappear when I hit the esc key.