Is that a limitation on the Moses SmartQ? Because on the N810, fbreader installs from the ubuntu arm repositories built into mer just fine.

sudo apt-get update
sudo apt-get install fbreader
fbreader

It is not the latest version of fbreader so it sucks on my epubs, but my non-drm mobipocket files work just fine and because you can remap the keys internally to fbreader (including fullscreen) it effectively seems to work similar to what is in maemo.