I installed SSRS 2008 R2 Developer Edition, but in the report manager, when I try to subscribe a report, it says
The feature: "Subscriptions to reports" is not supported in this edition of Reporting Services.
Any one can shed some light?
It is not supported on certain edition, as stated by Microsoft in the documentation :
http://technet.microsoft.com/en-us/library/cc645993(sql.105).aspx#Reporting
You need, at least, Standard edition, and Enterprise edition for data driven subscription.
Developer edition should have the same privileges as DataCenter (so maximum), so you probably are not using developer edition.
You can see the version being installed by running the following query : select @@version