Error while validating Web service operation transformation points to source in underlying error-free model

I'm executing the Updateable Web Service test and have encountered a new error.

I'm working on the operation that does inserts. The SQL is sending the update info to the view model that has the INSERT transformation. When I validate the procedure, I get ERROR: Products.PRODUCTSYMBOLS does not exist.

That actually exists as a source underlying the Updates model, not the Web Service. So how can the underlying transformation be valid and this one not be? (At least relative to this particular table in question.)

I'd be happy to find out it was something I did incorrectly, but the error message is pretty weak in conveying meaningful information.

Given the ubiquitous nature of Web services, I'm marking this bug as "critical". It could be a blocker, but I'll let someone else make that call.