Ok, so
- On N900, Maemo, it doesn't work. By "doesn't work" I mean that slots connected to dbus are never called.
- I tried dbus-send ... Introspect and it says that name com.nokia wasn't provided

So from that and from what you wrote it seems this is not right/working way. So
- I have to find other dbus paths, if I want to use dbus (QtDBus)
- telepathy-qt4 can not be used, if I understand you correctly
- or find something else (oFono)

Am I right?

EDIT:

I tried monitor dbus (dbus-monitor > watch.txt) and found some dbus addresses, but they're "org.freedesktop.Telepathy..." - so I can't use them, if I understand you right, because it works with telepathy which is not on meego...