If you are getting sound from that card using the cat, then I'm not
sure you need the isa stuff as the card is working and the kernel is
sending sound to it.
I suspect the problem is, as mentioned previously, artsd is getting in
the way. Your sound apps may be efaulting to alsa output with artsd
running and that causes a conflict.
artsd running prevents other applications to use alsa, but kaffeine and noatun are kde stuffs, so they should play without alsa and artsd running. (eg. xine can play audio tracks using artsd)
So, please try the above and report back.
A
raffaele