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They are simply con-ing you into buying their latest product, probably aimed at the 3rd gen. Marketing.

They'll push it on you, slap "compatible with 3rd gen" on it, and uninformed people will eat it up. There is no size difference.

Example: Its like incase selling the new "3GS Slider" even though the dimensions are the exact same.
 
I would be shocked if you put a 2nd gen and a 3rd gen next to each other and could tell any difference.

Maybe the rep you spoke with was thinking 1st gen vs 2nd gen??

I bet if you call again or email them you would get a different answer.
 
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