I am experiencing the same problem on Karmic (on my Gateway MX6920 laptop) too,
<code> $uname -r 2.6.31-14-generic </code>
my sound card is: <code> $lspci | grep -i audio 00:1b.0 Audio device: Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller (rev 02) </code>
and removing sl-modem-daemon was effective.
I am experiencing the same problem on Karmic (on my Gateway MX6920 laptop) too,
<code>
$uname -r
2.6.31-14-generic
</code>
my sound card is:
<code>
$lspci | grep -i audio
00:1b.0 Audio device: Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller (rev 02)
</code>
and removing sl-modem-daemon was effective.