VAT return box 6 figure appears to be including vat

The calculation is correct, with correct ex-vat amount in box 7 etc. but the box 6 figure is showing the inc vat amount. I'm assuming it's a problem or misreading particular to something done by me, myself, I, as I can't see any extended discussion in the support topics.

Cash accounting, 1 vat invoice in the period, 1 non vat invoice (new vat reg. taken up partway through Jan) so it isn't that tricky, methinks...