This is most probably due to the fact that you're using the wrong Sampling speed. It avered to work correctly when using the alsa-Drivers 0.9.x with x > 4 and 1.0.x with x < 2- but you'll have to recompile these. Under Mandrake however - these will only compile if you deactivate the verbose-printk stuff. In the Alsa-Driver directory, compile it using:

./configure --disable-verbose-printk && make && make install

or you'll get unresolved dependencies. Once this is done, make sure the alsa drivers are loaded using dxs_support=3. In the /etc/modules.conf - this will look like:

# Sound Stuff
above snd-via82xx snd-pcm-oss
alias sound-slot-0 snd-via82xx
options snd-via82xx dxs_support=3

And it should work :)