I'm a little surprised, as far as I can tell no one has noticed this before.
I did my undergrad at U of C, in 2002 they introduced an A+ grade. Before, an A was the highest grade you could get and coverts to a 4.0. For whatever reason, when U of C decided to add the A+, they made both A and A+ convert to a 4.0, an A+ was considered "an honour." (When they first introduced it, most profs didn't even award A+'s, since the GPA was the same as an A).
According to the scaling chart used by OMSAS for U of C, OMSAS converts an A to 3.9 and an A+ to 4.0. This is so simply and obviously incorrect. I could understand if the justification from OMSAS was to make a distinction between A and A+ grades mean something, however U of C (again, for whatever reason), does not!
I am in contact with someone from OMSAS, and so far their only response has been "There is no scale in the OMSAS system that allows us to convert A+ and A grades to the 4.00 scale within the same duration and so we are unable to make any adjustments to your GPA." Just because there is no scale, doesn't mean they should be lying about my GPA!
As I said, I'm shocked, because this means that every U of C applicant that has used OMSAS for the past 15 years has had their GPA calculated incorrectly!
I know this is too late to affect my current application and that the difference between 3.9 and 4.0 is relatively minor, I'm mostly just frustrated at the complete dishonesty of it.