Why are my apt-get update fetches so large? [duplicate]

I disabled apt.conf's deb-src lines per mikewhatever's answer. This brought it down, as with you, to ~6MB.

Then I noticed that when apt was getting the package info, it was going through 192.168.1.3—my squid-deb-proxy server (which runs 11.10; I haven't gotten around to upgrading it yet). Uninstalling squid-deb-proxy-client from the client brought the information download size back to normal.

EDIT: Aaand it went back to its old behaviour. I also checked the virtual machine on my Mac (fresh install of stable release the day it came out) which I boot up every now and again; package update information is a big download on it as well. I'll leave this answer up simply to document that this solution doesn't work. Beyond that, I'm stuck.