'05 Murano Won't Shift to Park

My wife reports that her Murano sometimes won't shift into Park after
driving to work. She said this has happened 3 or 4 times now. Seems
she has to wait about 2-10 minutes or so, then the shift column will
allow it to go past Neutral.

The dealer said they can't find anything wrong with it, and have not
heard of this problem.

Anybody experienced this with their Murano?