Thank you for providing so many details in your initial post.
This looks like a display adapter driver issue to me; can you check if an updated device driver corrects the situation? See http://forums.adobe.com/thread/945765
Thanks for the reply and the link. The driver update did not work because it says I have the latest one installed - even though the driver date is 10/8/2009. It's the Intel(R) Graphics Media Accelerator HD, version 220.127.116.118.
Can you believe that...the latest is from 2009?! I tried to install an updated version anyway - first by going to the Intel site. I found a driver update from Jan 2012 that matches my system, but the install aborts with the error message "A customized computer manufacturer driver is installed on your computer. The Intel Driver Update Utility is not able to update the driver."
So, I searched through the HP support site and finally found a link to my computer:
And I downloaded and installed the "same" driver anyway:
Intel Graphics Media Accelerator HD Driver ► 2009-12-04 , Version:18.104.22.1688 B, 29.91M This package contains the driver for the Intel Graphics Media Accelerator HD in the supported notebook/laptop models.
But it does not correct the problem.
Maybe this problem is because of an old graphics driver - but this is apparently a dead end for me.
Is there any possibility it is caused by something else?
Sometimes manufacturers modify original drivers, and then prevent installation of non-modified drivers. Sometimes that is not so bad, as to prevent inexperienced users from tampering with their computers.
However, other times we really do need newer drivers, e.g. to get new software (e.g. Flash Player) to work properly.
What I would do if I were in your situation is to download and install DriverMax - I have used it successfully for many years. Use the free version that allows up to two driver downloads per day.
But don't get carried away; only download & install the graphics driver. Let DriverMax make a System Restore Point before the installation, so that you can easily go back if something does not work right.
Hope this will solve your problem!