That is weird. I can't find part number 430-2931 at the Dell web site. There's a 430-2391 which is a Pro/Wireless 3945 802.11a/g PCIe Mini-Card for Dell Precision Mobile WorkStation M4300.
The 430-3127 indicates it's for the 11Z
The 430-3130 indicates it's for some Inspiron laptops (none of them a netbook)
The other 2 cards are for Studio 15, Latitudes, etc., laptops.
Hmm, the 430-3127 is probably the more likely given it works in an 11Z.
For the heck of it, I got in a chat with Dell Support. Here's what they said,
"I have double checked & there are no wireless N cards for the Mini 10 they are only available at the point of sale"
Why am I not surprised.