Hi luca
groups V2 and profile V2 do not work with jOpenSim since this has completely different database sources involved and jOpenSim basically works on the flotsam implementation.
It is important, that in your OpenSim.ini in section [Groups] is set:
and not:
Module = "Groups Module V2"
If you already have groups created by V2, there might be a possibility to convert them since flotsam and the "new" built in V2 dont really differ a lot (or maybe even just create a custom view as a workaround) but would need to investigate this more.
I'm working (since a while already) on a new version of jOpenSim, where this is definately taken into consideration.
Greetz
FoTo50