[Evolution] problem starting evolution for another user

[Alessio Dessi <alessio dessi poste it>]

Sometimes I've to run evo for another user, so I open a terminal and
"su" to the user, sometimes evolution start I'm happy another times
say   "Cannot initialize the Evolution shell."

evolution-shell-WARNING **: Cannot access Bonobo/ConfigDatabase on
wombat: (IDL:OAF/GeneralError:1.0)

there is any solution to this?

thanks in advance

Alessio