This morning I was greeted by a collection of apt-get failures. I use cron-apt on all my servers so I can quickly apply patches. A few of my servers reported the following error when they ran last night:

gzip: stdin: not in gzip format
Failed to fetch http://http.us.debian.org/debian/dists/etch/main/binary-i386/Packages.gz  Sub-process gzip returned an error code (1)
E: Some index files failed to download, they have been ignored, or old ones used instead.

A little googling revealed that it's some sort of bug in apt. The solution was pretty easy, simply remove all the files in /var/lib/apt/lists/partial.

The oddest thing about this issue is that it struck multiple servers of mine on the same day. Seems there must have been something on the Debian servers that triggered it. Maybe the web server crumbled and reset connections, leaving a partial file? That would be my guess but I'll probably never know for sure.