My 64gb 3G iPad has the exact problem detailed in this thread. I'm going to bring it in for replacement whenever the stock levels are there. Anyone else have this problem ? I only noticed it yesterday after using the iPad for a week but it's annoying the hell out of me now.
http://discussions.apple.com/thread.jspa?threadID=2444318&start=0&tstart=0
http://discussions.apple.com/thread.jspa?threadID=2444318&start=0&tstart=0