Domestic Reverse Charge VAT in Desktop

Hi, I have set up Domestic Reverse Charge VAT Codes in Desktop, but when I go and look at VAT Return it has entered the Purchase Invoice with the CRS VAT Code in Box 1 on Return and also in the Box 4 on VAT Return, so it is adding it in twice.  Is this correct as it does say -20% but adds it on.  Can anyone help as I need to send VAT Return this week.  I have checked and double checked but I have entered as stated by QB.  Many thanks in advance.