Purchased new? Or refurbished? It'd be interesting to get the history of that device serial# from Apple to see if it was perhaps a return or something, and was returned with a fake charger. Granted the store may be on the hook for not verifying it was a legit accessory before reselling it, but that IS a pretty good looking clone so I'm not sure I'd really fault anyone too much for overlooking it.
jgeorge|11 years ago