I had the same problem as you when I tried using the character editor; the file would open and I could make the edits, I could even close the program and open it again to see the edits I made, but I they simply weren't reflected in game.The problem is, on Vista and Windows 7 a program cannot write to the Program Files directory without admin privileges. Therefore, you have to right click on the .exe and click "Run as Administrator" every time. To make it permanent, right click on the .exe, click properties, go to the compatibility tab, check "Run this Program as Administrator."
This is what I did and it worked fine.
