Audio erratic with X-fi

[Tarrosion]

Hello,

I have an old SoundBlaster X-fi extremeMusic from about two years ago. Through those years I've had some driver issues and the like, but it hasn't been a big deal. A few months ago I upgraded to Vista64 (clean install). Since then, my audio has been quite problematic. I've experienced three problems, though I don't know if they're all soundcard related:

1) My speakers would occasionally stop outputting any sound whatsoever. A simple restart would fix this.
2) One day, a set desktop speakers I've used without issue for 3 or 4 years quite suddenly stopped working.
3) I swapped out those now dead speakers for a set of 2.1 (old harmon/kardon). That's worked fine for a few weeks until yesterday. When I turned the speakers on, they started emitting a faint static, and all audio played through them is extremely staticy and scratchy to the point of being impossible to listen to.

I'm running current drivers as well. Here are system specs:
Vista 64 Home Premium
AMD Athlon X2 6400+
8GB Patriot DDR2
Visiontek 4870
Soundblaster x-fi ExtremeMusic

Any help for resolving and preventing these issues would be much appreciated.

Thanks,
Tarrosion