Update Manager Not Working

[BlueAZ]

Hi, I've been enjoying a fairly trouble-free period with my Ubuntu 11.10 system recently! But I suddenly have a problem & can't find anything on it yet in the Forums.

Update Manager used to get updates, get my attention, & I would choose what to have it install, then it would. Now I'm getting a symbol in the top bar, a red circle with a white dash in it. When I click on it, it describes a problem. If I click on Show Updates or Install... I get the error message:

'E:Malformed line 57 in source list /etc/apt/sources.list (dist parse)

It asks me to report this, so here I am. The top-bar dropdown also says: An error occured & asks me to open Package Manager from the right-click menu [right-click on what?] or open a Terminal & run apt-get [apt-get what?] to find out what the problem is. As you can see, I don't understand these directions & need help! Thanks

[PhantomTurtle]

Can you post your sources.list (it's in /etc/apt/sources.list). I can tell you that way if it's okay to delete line 57 in it.