It's been 265 days since I made that post, but now that I'm reading it again, I see something that I didn't know when I wrote that post that I want to correct. If this doesn't help the original poster of this thread, at least it would help someone who happens to find this thread in which to try to solve his problem.
DON'T use Creative Auto-Update. If you do, THAT may be the reason you're getting the "Device not found" error code that you're talking about. Just uninstall all of the Creative programs and re-install them FROM THE ORIGINAL CD--and then do NOT use Creative updates of any kind--either Auto-Update, or updates from their websites.
I just installed a brand-new X-Fi Elite Pro soundcard that I bought about 3 years ago and didn't get around to installing it until now. Now, since it's over 2 years old, it's now on their "End of Life list". It was working fine--until I downloaded and installed all of the new drivers
and programs. Then I couldn't use the soundcard anymore, even though it WAS brand new, because for almost every program I clicked on, I got that error message, "Device not found". I uninstalled all the Creative programs and re-installed them from the CD, and voilą, everything worked fine again. Then I uninstalled the Creative Auto-Updates.