This was brought to my attention quiet sometime back, about how people who were using USB audio devices as their primary sound driver couldn't get anything that strictly depended on alsa to work, however certain apps would work fine. After doing a bit of research on this issue i think i found the appropriate fix for this issue.

The first thing you need to do is open up your favorite editor with sudo.

in kde you might use:
sudo kate /etc/modprobe.d/alsa-base
in gnome use:
sudo gedit /etc/modprobe.d/alsa-base

Once you have this file opened up scroll down to the line that looks like this:
options snd-usb-audio index=-2
Now comment it out with the # symbol in front of it so that it looks like this:

#options snd-usb-audio index=-2
Now you need to create a file in your home directory.. to do this use your favorite editor (kate or gedit) and use something to this extent:
kate ~/.asoundrc.asoundconf
After kate (or gedit if you used gedit) paste the following to the file:
pcm.!default {
type hw
card 1

ctl.!default {
type hw
card 1
Save the file, and exit the editor. Now reboot your system, and you should now have system sounds. PS be sure that you set your sound system to use alsa (if your in kde you can find this in kcontrol, in gnome you can use system>preferences>sound)

I hope this works for you guys!!