When I had my 4GB 2G iPod mini, the capacity was listed as 3.7-something GB, and I know that's because people define an MB as 1000MB and computers define it as 1024MB. The thing is, my sister just got a new 4GB green nano, and the capacity is listed as only 3.68GB. Why is there a difference between that and the mini in terms of capacity? I'm thinking that flash memory and hard drive memory might be different in formatted capacities, but what gives?