vitomins, I found what was wrong. The headers (Int - Bar, Juv - Chi, Liv - Cag, etc) weren't in the correct order. I do the calculations twice; first manually on a piece of paper then automatically using Excel. The thing is that I put the manual order of games in the Excel file. When I started the automatic process I didn't look at the manual order, so no harm done.
In short, all the results are correct, but I edited the table to rearrange the headers in the correct order.
For example, your result of Livorno - Cagliari was actually swapped with the result of Lazio - Atalanta. But since the sum of the results are the same, regardless of their order, your total points remained also the same.