I've opened Bug 2063 for anyone who cares or wants to help out by adding more info to it. Latest I provided in the bug is log from app. manager after trying to install again after a second attempt at flashing with new firmware with same results.

osso-application-installer 4.46, UI version 2
W: GPG error: http://catalogue.tableteer.nokia.com bora Release: The following
signatures were invalid: BADSIG CBFC2BECC6903E72 Nokia Internet Tablet Archive
Automatic Signing Key <integration@maemo.org>
W: GPG error: http://maemo-hackers.org bora Release: The following signatures
couldn't be verified because the public key is not available: NO_PUBKEY
5FD45CD3EA68E29D