Sorry about the lag in reply... work work work...
Check to see that you are indeed using the oss modules and not alsa...
and look for cmpci.o, if you're running alsa, then there will be a ton of modules listed with the name alsa in them, should be easy to sort out, if its alsa... well, let's check to make sure under whatever GUI multimedia mixer that it hasn't got the second line out muted. That would be funny, heck check under the mixer even if it is OSS's cmpci.
If its indeed cmpci its not necessary to recompile the whole kernel to just get the changes to the one module. We can just do the modules... see if you have your kernel source installed, it should be about a 150MB directory under /usr/src/ called linux or really... it'll be a symbolic link to a directory called /usr/src/linux-2.4.??
Which ?? Good question. If you haven't got your kernel source on there, no biggie, it'll be in RPM format on the CD, or .tgz... or wait, okay first, what distro?
Also make certain that you've got gcc on there too, the rest of the compiling toys should get installed as dependencies of gcc and the kernel source.