With gtcd running, and a CD playing through it, if you click around in
preferences, gnome makes sounds appropriate to the clicking. When each of
these sounds are made, the volume at which the CD is playing is reset to
zero after each sound. Manually increase the volume, then click around
again, and the volume drops back to zero.
What soundcard are you using here. Its most likely a kernel mixer bug
nm256 driver, NeoMagic 2200 AC97 Codec, in a Dell Latitude CPiA laptop.
I've not been able to duplicate this.
I just tested this on my Dell Latitude CPiA 366. It works for me (TM).
NeoMagic 2200 chip
This is probably the same laptop that Matt has. Mine is a PII 366.