Synaptic and respositories

[Bjørn Ingmar Berg]

Hello


When exploring the respositories, installing new applications, and
occasionally removing them again I've been using Synaptic.  I find it
to be a very good and effective tool, and I like being able to upgrade
_everything_ from one tool.
When folloving tips and how-tos from www.ubuntiguide.org I've been
using apt from the command line, as the guide has chosen that
approach.

I don't know if this "jumping back and forth" has caused my problem,
but so far that's the nearest explanation I can imagine.  Synpatic
seems to be partly messed up.  I wanted to add the Universe
respository, but even if I marked it's checkbox it didn't show up in
the respository list.

Then
sudo gedit /etc/apt/sources.list
showed I only had entries for Main and security in the sources.list file.

Rather than trying to reconstruct the file by hand I copied the sample
from Ubuntuguide over it.  (
http://www.ubuntuguide.org/sample/sources.list_extrarepositories )

Back in Synaptic I now have loads of respositories to chose from.  As
far as I can understand more than I really wish for.  But so far I
haven't messed with it again.

My questions:

Will it be "safe" to tell Synaptic to remove for example Multiverse? 
"Safe" meaning I can "bring it back" using the checkbox in Synaptic if
I want to.

Would it have been better to fix this problem some other way?  How?
I had the idea that perhaps I could use Sunaptic to reinstall itself. 
That would probably have worked.  N'est pas?  But would that have
brught back a sources.list file that was like the original in the
distro?


Regards,
Bjørn Ingmar