> Any suggestions on how I should handle this?  We've got no 
> diagnostics for
> this kind of thing because we expected that the WSDL would 
> keep it from
> happening.

We've got no diagnostics for this sort of thing because it is a protocol
level error rather than an SRW/U level error. There's nothing to stop a
nasty client ignoring the WSDL and sending bad stuff to an SRW server
but the SRW server would generate a SOAP fault rather than an SRW
diagnostics.

The SRU equivalent to a SOAP fault is a http error code so I think the
answer should be return a http 400 erro (Bad request)

Matthew