Ah, high-five!!
etlsport raised a good point - the magnetic plug won't pick up aluminum shavings, so if you are concerned about additional shavings in your oil (and you probably should be), change your oil & filter a couple more times in the next 1000 miles.
tom4bren & psychos - so do you still disagree with me about the threads being important to sealing the drain plug?What happened to Bart was what I was getting at - if you've messed up your threads so the plug doesn't stop tightening, it can't hold the gasket tightly enough to form a seal.
Yay!!! Mystery solved!!