its cause airline apps used different algorithms to compute Dual given countng towards your PIC and total time whereas Dual received addds to your total column but not your PIC column, or something to that effect. (even though you could be receiving instruction and still log it as PIC if your in any stage past your private. just another example why this program is horrible to use)
but the point is subtract 10 from section and see how it effects another section, then you can start to see how all the times interact with each other. It CAN be done. After 2 hours i got all my columns too add up correctly.

also it doesnt do decimal points, so i may round up or down, that can also account for +/-1 in some of your other columns