SSRS Deployment to Sharepoint Integrated Instance

We have a 3 server configuration on an Azure setup. SQL, Web (SharePoint) and Dynamics SL.

I'm trying to get SSRS reports deployed to the Sharepoint Integrated instance. I'm pretty sure the URL's are correct in the Report Server Configuration Console, but the bottom of the window says "You do not have sufficient permissions to depoy reports onto http://<ServerName>/Reports"

My user is SYSADMIN in Dynamics, Administrator in Windows Active Directory and my AD user has full control on the Sharepoint Web Part.

 Has anyone got this to work? 

Thanks