Yea, you are definitely not alone on this one. I can't delete any of the old phones off of the list and the list is full - so I cannot connect another phone.
I've got the same issue. The head unit holds 5 different entries for blue tooth connectivity and all are full. It will not let me delete any of the exisiting ones, so I'm out of luck trying to connect any new phones to it. Anyone have any ideas?