Downgrading all packages to woody versions

[David Gaudine <david@annette.concordia.ca>]

I use woody, and I have a few packages that came from an early
version of sid.  For these packages, dselect always shows me that the
installed version is the same as the available version.  For example, my
openssl and libssl packages show as installed version and available
version 0.9.6d-1.  (Woody has 0.9.6c-2, sid has 0.9.7a-1).  I do know how
to downgrade individual packages, and have already downgraded these
two.  However, how can I find and downgrade all other packages where the
installed version has a higher version number than the one in woody but
is actually older?

Here's how the problem happened:  When potato was stable I wanted to use
woody so I specified "unstable" in sources.list.  Then, when woody became
stable, I changed sources.list to specify "stable".  The problem is, I
made the change too late, so I picked up a some packages from sid.

David