Interest from installment sale income showing up twice on Schedule B

When completing form 6252, Installment Sale Income, I did not include the interest received on the loan. I did enter that interest in the 1099-INT section, as I received a 1099-INT from the contract agency.  On my Schedule B, the interest amount shows up twice, once with the name of the contract agency and once with the name of the business I sold. Why does it show up twice? 

 

If I delete the 1099-INT, the interest shows up only once on Schedule B. Is this the correct thing to do?