NoClassDefFoundError for PasswordCredential

I am trying to create a login module and I am getting to the point where I call

The portal (7.02 SP 15) is throwing a NoClassDefFoundError for the class javax/resource/spi/security/PasswordCredential. The class builds fine and all of the references are there in the build path. Is there something I need to add to the library sda in the provider.xml or in the LoginModule class jar file?

Any help would be greatly appreciated.

Thanks

Paul