SoundBlaster does not work

I have a kind of unique situation. I installed Ubuntu 5.10 on my first machine with the SoundBlaster sound card already installed. No problem. So on my second machine, I decided to go with the same sound card. It's cheap and under $30 and sounds good enough for me. On this second machine, I also installed WinXP. The sound card works on XP, so I know the card is good. On Ubuntu 5.10, it just doesn't work. I had to re-install Ubuntu 5.10 a second time already, but still there's no sound coming out of the card. If I rebooted and go to XP, the sound card works again. When Ubuntu boots up, the ALSA checking says OK. What's the problem here? Please help and thanks in advance.