*very* strange Photoshop CS4 troubles

Question

Hello,
I'm having 2 very odd problems with Photoshop CS4 I'm hoping someone here can shed some light on. I have been using PS since the early '90s and have never seen anything like these. I don't know if they are linked or if it's just coincidence. I have installed the most recent update (11.0.2) and the problems remain.
The first began about two weeks ago. Starting about 1/4th the screen width (1920) from the left to the left edge red becomes desaturated so at the left edge it appears orange. Very annoying. I use a Quadro FX 1800 video card connected to two Dell 2408 WFP displays via DisplayPort and I have the exact same problem on both displays. I have installed the newest hardware drivers, recalibrated my displays, etc., nothing fixes it. Today I saved a red swatch as a PNG and in both Picasa PhotoViewer and MS PictureViewer there is no shift in colour across either screen.
If I set the colour swatch in the tool palette to r=255,g=0,b=0 it appears orange if it's on the left side of the photoshop window. Move it to the right and it turns red. This is the kicker... If I leave it on the left and move the whole photoshop window to the right it turns red!!! perplexed.
Problem two is another mystery and it just started today. Frequently, and more so over the past week, I copy a colour channel from one image and past it into a channel of a newly created image. It's never made a difference if I was copying a colour channel to a greyscale channel, vice versa or colour to colour. It's always worked fine. Today however I can no longer copy a channel from one image and paste it to a channel in another with one exception. I can paste a colour channel to the alpha channel in a new image. Totally useless to me. Copying layers from one image to another is no problem.
I'm really stumped with these and though the first problem is a nuisance (when I look at a colour on the screen I also look at it's numbers so I'm already a skeptic)  the second is a show stopper. I would love to hear what people think of these.
jt

Answer 1

Interesting problem...
I'm assuming the orange looking window in Photoshop changes to red all at once when you move it, not gradually.
It sounds just as though a wide-gamut color profile is somehow being applied to just the left part of the screen, similar to what you might see if you had a small wide profile monitor on the left and another sRGB-like monitor on the right and the desktop spanning both.  Do your nVidia video drivers allow you to choose settings as though you have dual monitors?  Do they offer a monitor "identify" function, or the ability to configure "dual-link" DVI?  I believe that's the area in which you should look, and see if you can reset them to be configured for one monitor only.
Out of curiosity, what happens if you go into the Windows 7 Color Management dialog and uncheck the [ ] Use my settings for this device box entirely?  Do you find your color again becomes consistent when an image is moved from one location to the other on the screen?  Or is just the right side affected.
The Windows 7 image "Preview" viewer (e.g., right-click a .jpg image in Explorer and choose "Preview") is color-managed, by the way.  It will even apply a profile to part of its image (i.e., it'll do the right thing if dragged so that it is viewable on two differently calibrated monitors), so if I'm right about the system thinking you have two monitors in one, you may be able to see the exact vertical position where the profile change occurs.  It should also allow you to determine whether the problem is associated with Photoshop or on your system in general.
Consider this Windows Preview viewer run as noted above across the divide between an intentionally misconfigured monitor (with wide gamut profile) and a correctly configured one.  Look familiar?
-Noel