Alright, so this is starting to get seriously annoying ...
Every once in a while, I'll use the volume hotkeys on my iBook, and rather than getting instantaneous feedback, I'll get a repeating "click" sound, and then finally the volume adjustment window pops up.
If I press the volume keys repeatedly, up and down, the volume squares will slowly follow the motion I made, with that same click coming out of the speaker, until it finally "catches" and I get the regular sound and responsiveness.
Oh, this happens on my Mac Mini too.
I did some research on Google, and apparently I'm not the only one with the laggy volume problem. Tiger seems to be the culprit, as there are reports of this kind of thing never happening with Panther.
Are there any work-arounds? What's causing the problem? I've got 1 GB of RAM on both my Macs, they're not loaded at all, and they're not running out of RAM at all. It's not a system resource issue by far.