sources.list not updated properly by synaptic

[MarcRandolph]

Using 9.10 Mythbuntu beta disk, I enabled karmic-backports and noticed this what was added to the sources.list

deb http://us.archive.ubuntu.com/ubuntu/ karmic-backports main restricted universe multiverse
# deb-src http://us.archive.ubuntu.com/ubuntu/ karmic-backports main restricted universe multiverse

I assume the deb-src is supposed to be enabled.

Playing around further, since both lines for -updates were already there by default on Mythbuntu, I disabled them via synaptic. Both deb and deb-src lines were removed. When I re-enabled them, the deb line got tacked between the entries for -security way down at the bottom of the sources.list, and the deb-src line was missing:

deb http://security.ubuntu.com/ubuntu karmic-security multiverse
deb http://us.archive.ubuntu.com/ubuntu/ karmic-updates restricted main multiverse universe
deb-src http://security.ubuntu.com/ubuntu karmic-security multiverse