Mouse won't click w/ ASD 2.5.8 on G5

[kbfr08]

I'm trying to do calibration for my G5, so I have the ASD 2.5.8 disc, which is the correct one for my model. However, I can't actually CLICK on anything. The mouse works in OS X, but in ASD I can only move it -- i can't click on anything.

For what it's worth, the mouse does the same thing in the boot disk selection menu (holding option at startup). It's a wired apple pro mouse.

EDIT: figured it out, there was a conflict with the keyboard.