I've seen something similar. In my case, it turned out to be
because I
had a webpage open which had Flash on it, and Flash was using the sound
system, hogging it all to itself. Closing off that webpage (or the web
browser, I can't remember), got things back up and running again.
From time to time, I'll lose sound with Gaim, often because something
else was using the sound system at the time Gaim wanted it, and even
when that something else let go of it, Gaim wouldn't be able to make use
of it. I'd have to shut Gaim down and re-start it.
At times, applications that wanted to make a sound would not only not be
able to (because the sound system was otherwise occupied), but would
also hang or get stuck. It seems some software authors don't comprehend
"multitasking".
Looks like in my case that it's vmware causing my issues. I'm stayed out
of it all afternoon and have not had a mouse or sound problem since. I
remember when I installed the latest vmware player that it complained
about the version of compiler I am using (4.1 instead of 4.0 or
something), but I had it go ahead anyway. Maybe that's the reason, not
sure.
Thanks,
James