No Data-Driven Subscription button

I have created a report and published it on the reporting server. My connection is working, and I have followed the steps in the BOL tutorial for "Defining a Data-Driven Subscription" i.e. Credentials stored securely on report server, using windows credentials when connecting to the data source. When I click on "Subscriptions", I only see "New Subscriptions". However, when I look at other reports (not even created by me), I see the option to create data driven subscriptions. Can somebody tell me what I need to do to see this?I got it; the report cannot be in the "My Reports" folder.