It might be that Wakaba doesn't need him as much anymore. I guess that gives Po more time to hang out with her father, who probably needs a little help too.

Like Reiko said in episode 6, the lightposts don't bother them anymore. Partly because they're afraid of Po-chan, and mostly because Wakaba doesn't let ghosts bother her as much anymore. Her ability isn't as much of a curse now because it let her become good friends with Reiko.