Best of luck -- my nightingale is now sitting in a landfill somewhere -- used to work fine but developed some sort of problem that I couldn't resolve, even after a fresh/clean install of xp, setting up the same PC to dual boot from both xp and win98se, and even trying the card on a different pc. I needed mine for digital out ONLY and ended up replacing it with a chaintech AV-710, which uses the highly regarded via envy 24pt chipset (and runs a whopping $25 from newegg, etc.). Out of the box, the chaintech passes 48k bit-perfect digital out, but resamples 44.1k to 48k. A bios hack enables one to output everything without resampling. Note -- the chaintech only has an optical out. THe Maddog Entertainer 7.1 soundcard uses the same chipset and provides a digital in as well as out (optical only) and runs a whopping $36 -- but I digress . . .
Thoughts on getting your setup running -- 1) try the drivers found on the cmedia site, instead of the zoltrix drivers (be sure to first COMPLETELY uninstall the existing drivers), the cmedia drivers are the latest available, 2) be sure the card is set up to operate in 2 channel (not 4 channel) mode as spdif will only work in 2 channel mode, 3) if that doesn't work, you can try the maudio drivers, in my case that only made things worse. Maudio drivers are for the dio2448.
Finally, on my setup after not getting anything to work right, I ended up simply transferring dats digitally into my jb3 and then transferring the wavs to my pc for editing. Worked Great! -- otherwise, I recommend finding an maudio audiophile 2496, etc. which has similarly been proven to work fine for performing bit-perfect x-fers.