What's wrong with that? Well you would think the first way a person would test a phone's unlocked status is by trying sim cards from different carriers... let alone that I've commented on this before.
What? Are you absolutely confused? How could a simple test not be accurate? A friend purchased an unlocked iPhone. A second trip to the Apple store regarding a different issue resulted in a (very knowledgeable) Apple rep informing him that the iPhone was not unlocked - based on the info he saw on the receipt - The initial purchase was incorrectly processed by the Apple employee resulting in the sale of a Rogers locked iPhone. He tested a Telus and Bell sim card on this supposedly unlocked iPhone and neither would would work.
I fully understand understand the method in which Apple sells unlocked iPhones. You should read my first
post regarding it. I actually started a
thread regarding this at hofo, maybe you should check it out for more details.
And yes, it's a very serious matter, because there may be many people who went to apple to purchase an unlocked iPhone and may not yet realize that it could be locked.