upgrade errors, synaptic locked up

[Brian Craft]

When doing an upgrade to Hoary today, the first sign of trouble was a
package conflict: libavcodec2-dev (installed) conflicted with
libavcodec-dev (to be installed). The conflict was a header file
belonging to both of them.

It spit up this error after downloading all of the Hoary packages and
installing some number of them. I sorta thought it was the job of the
package manager to notice these things before starting the transactions.

At that point it aborted the upgrade. I marked libavcodec2-dev and
libavcodec2 for removal. That popped-up a dialog asking if I wanted to
remove packages depending on libavcodec2. Those were mplayer-custom and
associated packages (e.g. the mozilla plugin). After clicking on the
affirmation ("Mark for removal", or something like that), Synaptic
became unresponsive. I had to kill and restart it.

After that I just removed libavcodec2-dev, and some portion of the Hoary
packages were immediately installed. I had to hit "Mark all upgrades"
and "Apply" another time to get the remainder installed.

... and then my real troubles began.
b.c.