The issue isn't the Consolidated Calendar toggle, it is the data it uses when that is turned on.
If the Work Center is standalone (no defined Machine Centers), then the Consolidated Calendar should be turned OFF. This calculates capacity for the Work Center using the Work Center's settings.
If the Work Center has Machine Centers underneath, and you have Consolidated Calendar turned ON, you need to first calculate the Capacity on the Machine Centers THEN run the calculate capacity on the Work Center, which will total all the Machine Centers below it to give the capacity of the Work Center.
You don't have to use Consolidated Calendar for the Work Center even if there are Machine Centers, but I think it makes the most sense.
Best Regards,
Ben Baxter
Accent Software Inc