I am trying to get debian sid. Firstly, I installed a clean squeeze on my hard drive. I replaced everything in my 'sources.list' with 'deb http://ftp.de.debian.org/debian unstable main contrib non-free'. Then I performed these commands: apt-get update (no errors), apt-get dist-upgrade (took 10 minutes, no errors), reboot. But after reboot its version is still 6.0.7. Repeating 'apt-get dist-upgrade' works but doesn't change much (or nothing).
Upgrade debian from oldstable (squeeze) to unstable (sid)
debian;upgrade