Volume Control grayed out

Which volume controls are you looking at specifically? The Track's fader? Or in the Track Creation dialogBox?

Or are you in System Preferences?

On GarageBand, try clicking the arrow to the right of the 'lock track' button on one of your instruments. A box will appear, showing a tab saying either 'Track Pan' or 'Track Volume'. Next to this tab is a blue rectange, and if you click the the volume and pan should go back to normal.

eMac Mac OS X (10.4.6) Logic Express, Reason 2.5

eMac Mac OS X (10.4.6) Logic Express, Reason 2.5

It depends what you have selected as your input source

http://www.thehangtime.com/gb/gbfaq2.html#volumesliderdimmed

With either Line-In or the internal mic select on my iMac the volume slider is disabled as well.

I am going to agree with crustacean on this one. It appears that your track automation has been enabled. This disables the ability to change track volume and track pan in the selected track. Unchecking the blue rectangle should fix the problem. If you have not plotted any automation curves, just leave this box unselected (gray, not blue) and you will have all your volume and pan control back.

It appears that your track automation has been enabled.

No, she said the slider in the track info dialogBox. That has nothing to do with whether a track's volume curve is set.

The volume control grays out for me too whenever I select a FW interface. It has no volume control of it's own, so it comes with a software mixing screen and you control the volume from that. When GB2 asks to select the driver, selecting the FW I/O driver causes the Track Info volume control to gray out like you described.
By selecting a different driver in Sound Preferences in System Preferences, the Track Info volume slider comes back on. At least this works when I disconnect the FW I/O and it asks me to change drivers, but the Track Info is still gray though until I select a new driver in Sound Preferences too.

ManyToons

I'm sorry, I meant GB preferences, not Sound Preferences! But check them all. That slider doesn't ungray until I select a new driver in GB Preferences, in the Audio Tab: GarageBand Preferences>Audio/Midi>Audio Input.
Hope that works for you too.
MT

did you press the arrow button on the track and change to volume like that? Because if you did that is why you are haveing a problem.

Once again, she said the slider in the track info dialogBox. That has nothing to do with whether a track's volume curve is set.

jeez dont get your panees in an uparoar, excuse me for reading that

~ChRiS

No one's in an uproar, but you're giving wrong advice. Simple as that.