I fear your checkout form is a complete mess.
Looking at the default version, the flexibility in arranging the fields as per the Checkout settings section of the backend is pretty much non existing.
- I want the billingemail to appear below the billingfirstname and billinglastname fields — no chance. Even thogh I have changed the order in the settings page exactly as I want it, the email adress field appear right below the basket without moving. Looks stupid.
- I do not need billing address as my customers pay via paypal and will add those details there. I have therefore removed all mention of billing address in the settings — But oh wonder, the address field keeps appearing on my checkout page. Again, absolutely stupid asking for a billing address AND shipping address and then having the same questions being asked in paypal. For downloads I don't even need a shipping address at all.
Unfortunately this WP support form doesn't allow searching within one particular plugin's support forum. Therefore you might be asked certain questions over and over. I was unable to search if this questions had already been asked and answered.