I'm having difficulty with trying to upgrade my husband's iPad 1 to 4.3. It's currently running 4.2.1. When I connect it to iTunes on our updated MacBook Pro, I see the text that a newer version of the operating softweare is available. I hit the Update button, it extracts the software, and attempts to verify it with Apple. That's the point when I get a message that the iPad could not be updated. "This device isn't eligible for the requested build." I attempted downloading the iPad1,1_4.3_8F190_Restore.ipsw file directly, and using the option key to load that file when attempting to update. Same result. Is this possibly related to the fact that I've used this iTunes with my new iPad 2? I did successfully upgrade our other iPad 1 (the one I'll sell) when 4.3 was released last Wednesday. It's not good if the iPad 2 is causing trouble updating the iPad 1. Any ideas?