Baseline costs showing up incorrectly

I have a cost loaded baseline schedule that was originally received from the subconstractor is showing a Budgeted Total Cost of $23,835,030. I have received their latest update and the Budgeted Total Cost is $24,613,252. I have assigned the baseline schedule to the lastest update in order to vind where the variances in the ost loaded activities are. When I show the columns in the schedule for the Baseline Total Cost, the value is $24,742,960, not the $24,835,030 as originally established. I am completely baffled as to why this is happening. Does anyone have insight regarding this, or is it a bug in the system?