I'm gonna give this whole swapping thing a go, any suggestions?

[Grassmasta]

I recently bought an iPhone 3g off craigslist and it is repeatedly giving me a "this accessory is not compatible with iphone" message, even though nothing is connected. Initially I thought I had been had. So today I called the guy who sold it to me, and he was really nice about it and said that if apple wont take care of it, he'd be willing to pay for the repairs (score!). He also said that nothing had happened to it, but he admitted that after he installed 3.0 on it, he had seen the message and thought nothing of it.

So, tomorrow I'm going to go to the genius bar. The phone is under warranty until march of 2010, but is "not eligible for complementary phone care" (whatever that means). Being a T-Mobile customer and all, how do I need to go about this? My dad is on a legitimate iPhone contract, so I was thinking I could reference him as the account holder. Maybe say I'm doing him a favor and bringing it in. Will they kick up a fuss if it doesn't have a sim in it?

Any help at all would be greatly appreciated!

Bump!

Anybody just want to share a recent experience they had with a swap?