This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
I had two issues when trying to do the same. The first was the provider complaining that I didn't have a usable context. I fixed this by explicitly creating a JndiTemplate and configuring it with the usual JNDI context stuff. (Maybe because I'm running Weblogic at port 7011???)
At this point, I started getting the same error you did. On a long shot, I dropped the resource-ref param so that JndiObjectFactoryBean wouldn't supplement my jndiName with "java:comp/env/", since I don't supply this myself when manually getting a datasource. It worked. In the end, my key beans looks like this: