As I look more carefully at my prints, it seems that the problem may not be one of color accuracy, but rather of brightness. Prints from CS4 seem much lighter than what I see on my monitor and also lighter than prints from the same files made from CS3. I did recalibrate my monitor after installing CS4. Lighter colors, of course, appear to be less saturated.
Is there an explanation for this? I can always recalibrate my monitor, setting the White Point higher, but are there other matters to consider first?
Rob