Jennifer- re the ghosts on GHOST WHISPERER often being mad
SPOILER
Our thought on this has been that since they're ghosts who are in conflict that keeps them from passing, that's probably why they seem to be mad and then resolve the conflicts by the end of the show. The ones that aren't in conflict when they die presumably don't have the unresolved business (such as the guy who really died in that fire at the beginning of the show, seems like he must have been at peace with the decision to save the other person). My theory about the show has been that the ghost whisperer is actually visited by many ghosts, but we (the teevee audience) see the most interesting and conflicted ones on the show - I'm probably overthinking the theory behind the show's premise, though!!!