Interactive sort not working in Tabular View

I am just starting with Sql Server reporting, but I can't get interactive sort to work for columns with aggregate fields.

I am using the following query for DataSet:

SELECT
Store.ID as StoreID,
Store.Name as StoreName,
COUNT(*) as NumReservations,
SUM(Appointment.TotalBeforeTaxes) as Revenue
FROM Store LEFT JOIN Appointment ON Store.ID=Appointment.StoreID
GROUP BY ALL Store.ID, Store.Name
ORDER BY Store.Name ASC

For report, I am using tabular data view. Interactive sorting works great for StoreID, StoreName, but doesn't work for NumReservations and Revenue fields. I turned it on for all 4 columns.

What could be causing this problem?
Figured out the problem... It just doesn't work in FireFox. Seems to work fine in IE.