This is my first Debian (and Gnome) installation, which I have not used for 3 months.
Now I wanted to install some softwares using the Synaptic Package Manager, but I could not: any software I choose, Synaptic tells me that it is not available from the installation sources.
Refreshing the package list (from the Edit menu) seems to work (at least no error is shown), but nothing changes.
Plus, when I click on "Download list of changes" menu item in the "Packages" menu, Synaptic crashes. Other menu items in the "Packages" menu are sometimes active, sometimes inactive, but do not change anything. The package descriptions of uninstalled packages are empty, and are all marked unavailable.

I will badly need a ppt viewer in a few hours, and I cannot install a single package.

What happened to Synaptic?

Can you post up your sources list? Have you apt-get updated recently?

I could only get to internet for some minutes in the past week, in which time I coud install Open Office from debs using dpkg. So the problem is more or less solved.

Anyway, thank you for your attention.