Thanks Albert. Disabling the onboard soundcard did the trick - I still can't select the ca0106 as the default (default hardware tab from memory), it keeps defaulting to a GF104, which I think might be the sound from the graphics card (via HDMI), which I don't use and I can't obviously turn off. But, sound does work now and work correctly. I still can't get xmms2 to work (my preferred player), it starts and then just dies. I'll test it with strace later on. I'm trying to get used to KDE4 (I never migrated to it from KDE3). I've never gotten this soundcard to work in Linux before, despite a few attempts. Pretty happy am I!
As to soundcards, the onboard card doesn't support 24bit/192khz, my audigy does. I'm a bit of a Hi Fi nut