>that they couldn't handle dual monitors on Windows systems,

Progress!

To follow up on your suggestion, I went into my video control card software (AMD/ATI Catalyst) to disable my secondary monitor. I was then going to disconnect it and reboot Windows 7. In this utility I found a setting to "select the main desktop". See image below. My small, secondary monitor was designated as my main desktop so I switched that to my 27" Dell U2711. The problem went away! Now, images in CaptureNX2, Photoshop and Corel PSP look exactly the same as the images when viewed in Photo Mechanic, Firefox, and Safari. That is the way it should be.

So this is a color management quirk on multiple displays and perhaps AMD/ATI video cards.

Thanks Barry for the help,
Peter