apt-get update failing due to Hash Sum mismatch

if i do this on a development openvpn node:

apt-get update
...
W: Conflicting distribution: http://deb.leap.se wheezy Release (expected wheezy but got testing)
W: Failed to fetch bzip2:/var/lib/apt/lists/partial/http.debian.net_debian_dists_wheezy_main_i18n_Translation-en  Hash Sum mismatch

:(

*(from redmine: created on 2013-04-15, closed on 2013-04-30, relates #2195, relates #1348)*