Sorry,
I meant this:
I installed the app while I was connected to wifi
I trusted the wifi which I was connected with
--everything worsk great--
I was leaving, switched too 3g network(manually).
I came home, n900 connecs automatic to wifi(the trusted one)
-- it doenst work anymore--
currently: I'm connected with the trusted wifi, but my n900 still locked after 5 min...

Thanks