DS Web Browser, 2 versions! Options

[unitself]

Hey e'rybody!
Just a quick note if you're interested in getting the Web Browser for the DS.
There are two versions - One for the Lite and one for the original style. It comes with two carts - one DS style and one GBA style (which is a memory expansion). The cart is where the issue is. If you have an old stule DS, the Lite cart will not fit into the GBA slot. It's smaller and has a tab sticking out of it preventing it from going fully into the slot and making contact. The writing for this is super tiny and on the lower left of the box.

I bought the wrong kind last night and the store did not have the other kind when I returned it this morning.

What pisses me off is that I have been checking this browser out for over a year now and nowhere have I ever read anything about there being two different cart sizes. So, I never even thought to check for anything like that.
Why would they do that? Arg!