In case you’re interested, I did find out what the problem is. It’s a bug in the VirtualBox guest additions for 4.1.0. I did not have the problem until I installed them, and could downgrade to the previous version, and the problem went away.
Once I figured that out, I found at least one other post on the web with someone who was having the same issue with some graphics software, like CorelDraw.
Thanks again for the help.