PowerPivot: Sorting based on a Values column

I'm using Excel 2010 and PowerPivot. I've got a Pivot Table where I'd like to sort the data based on what's in the Values column (the third column). I would think that simply clicking Sort>Largest to Smallest would work, but it does nothing. I can sort by the ID column, and by the Type column (both are Row Label columns in the Pivot Table), but not by the # of times Scheduled column (which is a Values column in the Pivot Table). Is there some trick, or am I missing something obvious?

Thank you!

ID Type # of times scheduled
17341 Block 6
17342 Block 7
17344 Block 7
17352 Block 4
17353 Block 6
17354 Block 7
17355 Block 6

EDIT: I hesitate to include the actual workbook because I work in the adult entertainment industry, and the full spreadsheet contains some material that would not be "Safe For Work" (not images or anything, but racy movie titles).