This is not a request for support with a problem. It is a complaint. The scoring system used for Internet Spades is different in Windows 7 than it was for Windows XP.
In Windows XP, if one opponent bid nil and the other opponent bid to take X tricks, if neither opponent made their bid then they would be scored -(X * 10) - 100, regardless of whether or not the number of tricks both opponents took equaled X. The tricks taken by the opponent bidding nil would be counted as bags, but would not benefit the team by being counted toward the total number of tricks taken. This was the correct practice. The team should not benefit from tricks that it specifically said it would not take.
However, in Windows 7, the tricks taken by the partner who bid nil are counted toward the bid made by the other partner. The only way to set both opponents is to make sure that the total number of tricks taken by both opponents is less than X. The opponent who bid nil gets to count his or her tricks even though he or she said that no tricks would be taken.
Personally, I consider that to be a bug in the scoring system.