Ed, I don't have access to a computer with Excel at the moment, so I figure I might ask if you're referring to the 2009 or the 2008 Suffield Shakedown. I ran those numbers with the data on TBA for the 2008 Shakedown.
Oh, also, a note on how I'm running my calculations. In Excel, I created the matrix of the matches played with each team, took the inverse of it, and multiplied it by the total score vector as was my understanding and as Excel allowed. I have the file here on my thumb drive, so I've uploaded the spreadsheet
here.It should be on a sheet named Match Matrix, I believe, though I don't know if the test matrix is in there. There should be vectors in there as well to enter the scores for OPR, the margins, and it should spit out WM and OPR next to them. I think I just used letters to label them, and can't remember using anything really obscure, so they should be easy to identify. If my test matrix isn't there, there will be an empty matrix for match data, and then it'll spit out its inverse next to it or below it. I've done both, and can't be sure which...
If I've done something wrong, it'd most likely be in the math there, I'd think.