Options that become mysteriously grayed out?

Every now and then while editing images in CS2, some of the tools in the submenus become grayed out and the title in the window Im working in says Quick Mask/16.
For example: under Image/Adjustments, the Hue/Saturation option becomes grayed out for some reason.
Is anybody familiar with this action? How can it be prevented or is there something I need to turn on or off to continue using these tools?

some adjustments aren't available in 16 bit mode. do yout 16 bit work, thwn switch to 8 bit mode to finish

Are you trying to apply that adj to the correct layer in the image?

coreypolis wrote in post #2257716
some adjustments aren't available in 16 bit mode. do yout 16 bit work, thwn switch to 8 bit mode to finish

Can't switch to 8 bit mode cause it's grayed out also

A468BU wrote in post #2257743
Are you trying to apply that adj to the correct layer in the image?

Yes, I've been wworking on the same layer from the start

maybe you can't be in the quick mask mode and switch between.

coreypolis wrote in post #2257879
maybe you can't be in the quick mask mode and switch between.

How does Quick Mask work? Can I go back to my original settings from where I am?

Oh yeah, can't use Clone Stamp or the Healing Brush as well...

If this is any help, I just found out that Quick Mask is a channel...