I've noticed when I use xmms then set try to set the volume to 100% via the volume bar on the main window it completely goes mute. xmms will continue playing wihtout error. Just no sound.. The internal specker will still beep though... I've had this problem kernel from 6.1 and to the lastest 6.2 kernel.. I tried fooling around with xmixer and audio mixer, but that didn't help.. I had to rmmod the audio and cs4231 module and the insmod them back in to make the sound come back..
This sounds like a problem with the OSS compatiblity mixer in the kernel.
The mixer wrap was fixed in later kernels