I am so curious about the origin of that particular "rule". You're right though, it's just so ridiculous you can't help but laughing about it. Even though it's throwing a monkey wrench in the plans.
Good luck and make sure to post if you find out where that comes from.
You know....that got me thinking, my godfather is one of those catholics that knows EVERYTHING about the symbolic origins and particular doctrines of anything to do with the religion as well as other faiths. I'm going to try and find his email and ask if he's ever heard of that.