The only thing I can tell you is try to find out which other card shared the IRQ before you replaced the sblive card , and now , in your mo bo user manual and make it like before .
Otherwise in the instruction manual are 5,7,9,10 possible standard irqs .my sb live is on the 3rd pci slot IRQ5 together with my DXR3(ct dvd encore) on pci slot 5 .
Normally the first pci slot shares IRQ with the agp slot .
My pci slot 6 is a slave slot for cards not needing busmastering and is free , my first pci slot is also free.
I think you simply have to try other slots , or restore the original settings .
good luck