You've probably moved it several times looking for it. I lost the ipod once for a couple weeks. Look absolutely every where it could have been.
I moved a stack of papers that I had checked several times and found it in between a couple envelopes.
So it will show up eventually. It's a like a puppy when you're trying to catch it, when you ignore it, it will come to you...well in this instance you'll stumble on it.