PS CS vs. CS2 - Brightness/Contrast conflict

Has anyone seen a problem where, with both PS CS and CS2 co-installed, the Brightness/Contrast adjustment in PS CS has no effect upon an image where it does work in PS CS2? In the simple case I was working with, the image was a standard 8-bit RGB color image, and I first noticed this when editing the main layer. A flattened copy of the image, saved as a JPEG, demonstrated the same situation. I've not got the time to explore this any further at the moment but will do so tonight. But, if anyone has seen such behavior, I'd appreciate knowing about it.

Thanks,

Daryl

Well, for the time being, I'm puzzled. Now home and working on my own PC, I'm not seeing the problem I described in using the Brightness/Contrast adjustments, regardless of the operation being performed in PS CS or CS2. What would be different about the PC I was using at work, I'm not sure, but I'm not going to worry about it for now. In any case, if anyone should see similar behavior and document it here, maybe it will be helpful in identifying whether a genuine problem exists or not.

Thanks,

Daryl