Okay, I am reposting this here on the combined forum. This was pulled from the Mac forum (http://forums.adobe.com/message/3525659), however I am having the exact same problem on a PC running CS5.
When I "let go" of the "work area" window on the LCD monitor it rather visibly changes the color tonality (so much so that white turns yellow). When I release the image, why is Photoshop altering the color space - when other programs display evenly across the monitors? Am I to assume that releasing the image triggers the second monitors profile? Maybe I simply need to use the same profile for both monitors (which would be strange because this was a problem before I assigned any, and is still a problem after running calibration)? I will experiment more tonight, but any help is greatly appreaciated.
I've been using Photoshop for years and never encountered this before, however this is the first time I've added a LCD monitor into the mix, as my old Viewsonic finally died. I will be replacing the other monitor with a LCD in the near future, it will be interesting to see if the problem magically resolves (assuming I can't figure it out in the meantime)
P.S. - as to the forum merger - why? It would have made more sense to simply be able to flag a post as pertaining to both operating systems, and thereby have it appear in both threads. That way you're not burdening everyone with threads that do not apply, and you're not losing all of the old threads (which are now read-only for some reason).