Some times when I undo something and wanna redo it ,sonar won't let me to do that and they both are gray out. Looks like just load a project and there is no undo and redo. It is not always acting like this. it is randomly. Any one has any idea what is the issue?
Thanks 

Is it a volume change that you're wanting to undo/redo?
If so, Sonar doesn't undo/redo volume changes for some reason.

g_randybrown
Is it a volume change that you're wanting to undo/redo?
If so, Sonar doesn't undo/redo volume changes for some reason.

If this is the case, right click the fader and choose "Revert to nnn"

Bristol_Jonesey

g_randybrown
Is it a volume change that you're wanting to undo/redo?
If so, Sonar doesn't undo/redo volume changes for some reason.

If this is the case, right click the fader and choose "Revert to nnn"

As embarrassed as I am to not have known this until now it's very good to know.
Thanks Jonesy!

No It is not volume . It is lots of things like pasting, cut, delete, recording midi or wave. But as I said it doesn't always do this. It is randomly which is so frustrating. like last night I accidently copy and past my piano track 7 times instead of 1 and save the project I found out  I did wrong and tried to undo the paste but unfortunately it didn't let me to undo and I had to manually delete the piano note by note because it was pasted over the other recorded piano in the track. really messed up. :(