Keyframe issues
 

Following the book "Learning Maya 7 | Foundation", chapter one, lesson two, I keyframe Rotate Y on all groups on frame 1, then go to frame 20 and set a different Rotate Y for all groups and go to Key Selected, but it's grayed out, and Rotate Y is red and set to zero. What am i doing wrong?

How can I reset Rotate Y on all keyframes and delete all the keyframes?

I'm trying to make a solar system animation that spins all the planets with different speeds around the sun, and also spins all the planets around themselves.
I'm also wondering why I am instructed to rotate the groups and not the objects(planets) by themselves.

Thanks in advance
~Lennart

BUMP

None of the nine viewers had an answer? Come on please, I really need this to work...