The reason Kieron asked for the savegame is because changing simuconf.tab after you start a game will not affect the settings -- they are saved with the game. Did you change the settings in simuconf after you created the game? If so, you'll need to start a new game or access the secret settings dialog:
In that dialog you should be able to find and increase the passenger factor.
P.S. Why don't you use a more recent release of simutrans (112-3?)
That quite worked thanks however, I seem to have messed up again with it. After exiting, I still increased the pax factor in simuconf tab and when I returned to the game this fatal error occurred:
FATAL ERROR: planquadrat_t::rdwr() - Error while loading game: unknown ground type '8' Aborting program execution ...
Hope this can still be fixed, I don't want to loose the huge map I manually made for the game.