Question: I briefly enabled updates from jaunty-proposed to see if there was an updated for a particular package that was causing me issues. There was a couple of updates for other packages which I installed and now I'm having issues with my ethernet. But I can't remember which proposed packages I installed. 

How can I find out which packages have been installed from jaunty-proposed rather than jaunty-updates?

Answer: 
Aptitude has an incredibly rich set of [search patterns](http://algebraicthunk.net/~dburrows/projects/aptitude/doc/en/ch02s03s05.html). In your case, you'll want `~i` (for "installed") and `~A<archive>`, like so:

```
aptitude search '~i ~Ajaunty-proposed'

```

As an example, I have a few packages installed from 'hardy-backports':

```

$ aptitude search '~i ~Ahardy-backports'
i A bacula-common                   - network backup, recovery and verification
i   bacula-fd                       - network backup, recovery and verification
i A libsvn-perl                     - Perl bindings for Subversion
i A libsvn1                         - Shared libraries used by Subversion
i   rsync                           - fast remote file copy program (like rcp)
i   subversion                      - Advanced version control system
$

```
There should be a record in /var/log/apt or /var/log/dpkg (you may need to double check the names; I think the apt one is a directory and the dpkg one is close to the name of the logfile) that lists what packages and actions were taken and from that you should be able to figure out what happened.