On my N900 when I run apt-get update I get the following output:

:
:
:
Fetched 988B in 22s (43B/s)
Reading package lists... Done
W: Conflicting distribution: http://repository.maemo.org fremantle-1.3 Release (expected fremantle-1.3 but got )
W: GPG error: https://downloads.maemo.nokia.com ./ Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY ADB4438160A655EF
W: You may want to run apt-get update to correct these problems

There appear to be two separate issues here. Anyone can give some hints on how to fix this?