MAMEWorld Forums - The Loony Bin - Anyone dealt with moving a king mattress before?

My wife and I ordered a king mattress over the weekend, and now I have to figure out if we can actually get it into the bedroom. (She did all the research into it, but of course it's my fault if it doesn't fit.)

My only worry is the stairs to the upper floor. We have kind of a weird staircare with walls on both sides that ends in a doorway at the bottom. Clearance from the first step to the top of the doorway is about 74". What's really freaking me out is that the shortest distance between the 4th or 5th step and the top of the doorway is only about 48 1/2", which means I'm going to have to fold the sucker nearly in half to get it through. Once I'm through the doorway, I'm golden. The ceiling in the stairs is way high and the doorway at the top is at least 78".

It's a latex foam mattress, so hopefully it's a bit more flexible than a traditional one, but does anyone know if I have a prayer of getting this thing up the stairs? I can cancel the order now, but once we take delivery we can only get store credit for it. Which basically means I'll be sleeping by myself in the dining room on a great big mattress.