Problem with SB 5.1 and directx

I'm having a problem with my Sound Blaster Live 5.1 card. I think it may be some sort of hardware conflict. Whenever I run dxdiag and try to run the 3d test the computer freezes. If I disabled the SB drivers the tests work properly (and so do games w/o sound of course). I've tried assigning different IRQs, but they haven't solved the problem so far - in fact it got worse with some other IRQ settings. There doesn't seem to be an IRQ conflict atm: the only other entry at system information is ACPI IRQ holder for PCI steering. I guess thats ok? I'm using the latest DirectX. The sound card plays music and sounds just fine. I'll continue going through all IRQs and see if that helps, but other than that I'm running out of ideas. If you have any ideas what might be wrong, please help!