Manually Sorting Pivot Table Row Labels

Hi all!

I am working with a PivotTable (and I'm new to them, so be gentle!) and I need to sort the table by row label manually. I have highlighted the following excerpt from the applicable Excel Help file.

Sort data in labels
...
Optionally, to customize the sort operation, on the Options tab, in the Sort group, click Sort.
In the Sort <Field name> dialog box, select the type of sort that you want by doing one of the following:

To return items to their original order, click Data source order. This option is only available for OLAP source data.
To drag and arrange items the way that you want, click Manual.
To select a field to sort by in ascending sort order, select Ascending (A to Z) by, and then select the field from the drop-down list.
To select a field to sort by in descending sort order, select Descending (A to Z) by, and then select the field from the drop-down list.
Tip Read the Summary section at the bottom of the dialog box to verify your choices.

My problem is this: after following the above steps, then clicking Manual, then ok, I cannot drag and arrange the row labels in the PivotTable. I'm sure there is a simple solution to this problem, but if someone could walk me through it, I would greatly appreciate it!