Aqua's right. They rise up from their graves and head straight for the entrance, get in cars, and leave. Before the bug, they would just hang around the graveyard, talking to each other, reading books, etc. and you could easily meet and talk to one. I was able to resurrect some by bringing Ambrosia and setting it on the ground, but that was before the bug. It might be fixed sometime, but we have no idea when.