xmlns:xsi Strikes Again

I thought I would work through a simple JSF tutorial - very easy, no data sources, just three JSPs. But when I try to deploy it to my OAS 10g 10.1.2.0.2 dev server, I get the dreaded

Deployment failed: Nested exception
Resolution:

Base Exception:
java.rmi.RemoteException
deploy failed!: ; nested exception is:
oracle.oc4j.admin.internal.DeployerException: Unknown assembly root-tag attribute: xmlns:xsi. deploy failed!: ; nested exception is:
oracle.oc4j.admin.internal.DeployerException: Unknown assembly root-tag attribute: xmlns:xsi

This is a compatibility problem between JDeveloper 10.1.3 and OAS 10.1.2 that I've run into before. So I searched my JDeveloper project folders for xmlns:xsi, found two files, removed the offending tag and I still get the error.

WTF?

This is why there's an I Hate Oracle club. . .

Screw it. It's Friday afternoon; I have a sailboat race tomorrow, and, unlike Larry Ellison, I'll probably win.