I own a Creative Sound Blaster X-Fi Titanium Fatal1ty soundcard, an awesome piece of hardware, though I’ve always experienced audio issues with it on Linux (damn drivers!). My research showed that those bugs are a result of interactions between Pulseaudio and ALSA, and that the available fixes do not work for everyone. I’m glad they do work for me.
The trick is disabling PulseAudio’s timer-based scheduling. Fire up the terminal, then type:
su -c "nano /etc/pulse/default.pa"
Look for the line that contains load-module module-udev-detect, and append tsched=0 to it. Now it should look like this:
load-module module-udev-detect tsched=0
Save the buffer and exit the editor, then restart PulseAudio with the following commands:
pulseaudio -k pulseaudio --start
Now your audio should be crystal clear. If it’s not, you will probably need to use another fix. Yeah, that sucks. :P