If you don't change the skill levels and just give yourself the extra 10 skill points, do you still get the error?
In Vista, try running the save editor as administrator (right click program/shortcut).
If that doesn't help, try copying the save folder (or just the data.000 file) to another location to edit from. The program was released before Vista was out, so maybe it has a problem with how Vista relocates the savegame folders, or the length of the 'users' path, or something.
If you have or learn level 1 in Sword Expertise or Augment Damage (the starting skills for the male warrior), the next time you save and load the game you will have level 2 in these skills.
