Sure, perhaps Obama was enrolled in elementary school in a Muslim country where his parents decided to list him as Muslim. You know what? When you're surrounded by Muslims, that's just basic good parenting if you value the survival of your child. Plain and simple.
Besides, what you believe as your religion at age 13 is pretty much irrelevant to who you are as a person. I don't call myself a former Buddhist just because I got really into Zen and the Art of Motorcycle Maintenance when I was a high school freshman. I don't call myself a former pagan even though I played a lot of Dungeons and Dragons, and I don't call myself a former Satanist even though I once read some stuff by Aleister Crowley. In fact, to do otherwise, to claim that I was once a practicing Buddhist or practicing Satanist, would be flat-out factually incorrect.
And the question is: Who cares? Whether or not he was ever a Muslim in his youth has very, very little to do with what his opinions, stances, and actions are now. It's pretty much entirely irrelevant to the question of whether or not he'd make a good President.
An Obama Presidency would be a train wreck in a hundred different ways. We've got real, substantive material we can smack this guy on. Let's not waste our time, energy, and most importantly our credibility by pursuing this ridiculous "Obama is/was a Muslim" canard. It's just not worth it.
I don’t think it is the muslim thing as much as it is the lie thing and shame to be around Muslims.