I _had_ an SBLive MP3+ in my machine at first. After spending weeks of try to fix lots of random freezes/lockups, and sound crackling/popping, I finally bought a Yamaha 744 card and switched to that. Now, no more problems. ;-) Yes, I tried all the suggestions on the forums (switching slots, reserving IRQs, playing with PCI latency, etc.) but no fix. I heard that some people have had problems with older SBLive cards on the A7V (I got mine in Dec. 1999). Most people without problems seem to have purchased their SBLive recently (within the last few months), so I don't know...
If you really want EAX 2.0, etc. then maybe try a SBLive. If you just want basic sound output (listening to MP3s, playing games, etc.) then maybe look for a different cheap card (i.e., Yamaha). No problems with GeForce cards, either...
Just my opinion...