This happens occasionally and seemingly at random. I'm a bit of a do it yourself 'er so I've dissected most of the center console, mainly because the shift pin bent (extreme force was applied) and the rod slipped off. I don't think its an interlock switch because i can hear the mechanism release when i hit the brake and its a bit "spongy" when i pull back on it, not the regular hard stop. I've tried different parking arrangements, up hill, down, with and without parking break, flat ground. I've taken notice of temperature from cold to warm, outside and engine, but none of these seem to be a factor. Like i said, its random, completely.