I still have a newer version (monav_0.3.1+hg4f0f7f48e173-1_armel.deb) that works with the old mapsets from 04/2011 around, but can't currently upload. (Why is there a size restriction which is set too little for this board anyway?) So, check if this build (monav_0.3.1+hg4f0f7f48e173-2_armel.deb) is working for you.

Btw monav development seems active enough, just check their project pages and especially the issue list which gets updated and cleared.