First of all, is Photoshop updated to 12.0.4/12.1?
Second, do you see that behavior with any and all files, or just that particular one?
Third, how much available HD space and how much RAM?
Have you tried resetting the eyedropper tool?
Click on dropdown box of tool in upper left hand corner. Then click dropdown box arrow in right corner of the window.
If that does nothing reset the preferences.
Start photoshop and immdeiately hold down the option + command + shift keys. (Windows Alt Ctrl Shift).
You should get a reset window.
It is a little tricky so if you see the splash screen you are too late.
Sounds like the color picker dialog is opening off-screen.
Have you used a second monitor on the system that's not available at the moment?
Thank you all So Much for your help! I am new to these online forums and feel very appreciate of your quick advice, as tech troubles can be so frustrating and daunting.
Noel, you were totally right! The color picker window was opening on my wacom tablet which was on sleep mode, so I couldn't see that this was happening.