discrepancy in ipad model numbers

[MrShankly]

I'm planning on buying the new ipad and have been doing some research and pricing online. I've decided on the wifi-only 32gb in white.

Here's my problem: I've noticed that the apple store lists this as model MD337LL/A whereas most other websites(newegg, best buy, amazon) list this product as MD329LL/A. I've searched the internet and can't find much history or information on the MD337 number. Does any one happen to know why there is some discrepancy in the numbering? I'd hate to unknowingly order an "older" device. Any one know what gives?

(I did a board search before posting, and I hope this hasn't already been discussed)

Thanks!