mozilla-browser (= 2:1.0.0-0.woody.1)
You are trying to get the woody 1.0.0 version of mozilla.

try this apt-get command:
apt-get install -t unstable mozilla

or go to www.apt-get.org and get an unstable URI for mozilla and put it in your /etc/apt/sources.list file (then apt-get update).

HTH

rock