I figured out simple trick... I downloaded .install file to N800 and corrected it with text editor. It seems that currently repository for diablo is not present, so you just simply enter older repositories (don't remember exactly - I'm writting out of my memory)...
Check URLS in install file and set it accordingly. For me Orbiter seems to be working ok (beside few problems that I've already posted mantis thread and showed to NiteMan...).
The trick is that newest FW is looking for packages in ..../diablo/... directories, but most of repositories don't have that entries yet...