I'm using WinALDL and haven't noticed a problem with the numbers being off. I also have an OTC so that I could compare the two numbers. Sorry that I couldn't help. There are some settings that you can change within the program like for TPS at 0 percent but I don't remember seeing one for IAC.
There is a right and wrong way? I didn't notice that when I replaced mine for the first time about 5 months ago. Sure hope I didn't do the same thing. How did you know or find out?