1.2gb used even when I reset then restore from itunes?

I have had my ipad mini 2 for 2 days and i think there may be a problem.

Its 16gb, ios 8.4 with a capacity of 11.9gb

Ive done a full reset and a restore from itunes but its available space is 10.7gb

There is an unexplained 'used 1.2gb' when i check usage.

I check itunes and it says there is an odd 10.97gb free and says 859mb documents and data, 120mb other.

This is the most odd part, after i reset: almost the full 11.9gb is free however the used space rises as if something is downloading, i turn off wifi and it stops.... turn it back on and it rises till it reaches 1.2gb.

I doubt this is an update as it say its ios 8.4 before it has fully become 1.2gb

Im thinking of changing apple id to so there is a different icloud or can someone tell me that the 1.2gb is part ios app updates or something.