1.4-2 is different from 1.4.2 - a dash is different from a period. Basically, the "-2" and "-3" refer to different builds of the same version of Maemo Mapper. 1.4.2-2 is the "1.4.2" version of Maemo Mapper, built for the 770 (maemo 2). 1.4.2-3 is the "1.4.2" version of Maemo Mapper, built for the N800 (maemo 3). 1.4-2 is the "1.4" version of Maemo Mapper, built for the 770(maemo 2). 1.4-3 is the "1.4" version of Maemo Mapper, built for the N800 (maemo 3).