And they had just begun to find closure, only to find there is none yet. Sucks to be Bobby as well. Poor guy.

Yeah...remember in Death Takes a Holiday? When Sam and Dean met the ghost kid who was still living with his mother - and they told him that his mother couldn't move on and be happy again as long as she could sense his presence as a ghost? I think that's coming into play here too. Which sucks for the boys and for Bobby.

Good point about the ghost-absorption vs. salt-n-burn!