OK.
I have the exact same soundcard, and i had the exact same problem
but i was able to fix it.
Creative released a update which supports OpenAL. It's kinda hard to find on their site. Without this update, your computer blanks out, and either returns an error message, or you have to restart. This problem annoyed me for some time untill I found the update.
Here is the website that has the update, its a couple down. It lists
"Added OpenAL support"
At the end of its discription
X-Fi Updates
I really hope it helps like it helped me
Edit::: Ok I actually have a ExtremeMusic X-Fi, but when I looked under ExtremeAudio updates, it didn't include a update that added support of OpenAL. So im not sure if the XtremeMusic update willwork the same on XtremeAudio. Funny that the Audio one didn't have the OpenAL update