Difference between "current" and "joint" in What-If Worksheet

Hey everyone,

 

My husband and I have very different sources of income and I love the What-If Worksheet for figuring out how much of our taxes owed pertain to whom. But I don't understand why the  first two columns aren't the same -- "current return (MFJ)" and "MFJ." They're both supposedly reflecting our joint return.

 

In many rows, they're the same, but in many they're not. In one case, the difference is extreme -- "current return" has -31,000 in rents/royalties, while "MFJ" has -1800. Why the difference?

 

Thanks in advance for your help,

Karin