Problems with loading data to Feature Class

Hi,

I'm trying to add some point data to a point feature class. I'm loading the data to the feature class to add records. The idea is that the added records will take on the same fields as the existing feature class. It appears to do that, but I have fields for, Plotrow, PlotCol, X_Coord, and Y_Coord, that are coming up as nulls. I must be missing a step in this process but I can't figure out what it is??

Jess