I thought that you are generally expected to write your WDSL by hand, that the generators don't work.

Well, some generators work ... but that's not necessarily a good thing.

The problem is, not all languages implement their data structures in the same manner -- most modern languages have a concept of an associative array of some sort ... but is a struct, a dict, a mapping, or a hash? Are any of those even the same thing? Does it support multiple values for a given key? Does it require a specific order? Does it allow elements to be missing?

It seems like a rather stupid thing, but what works in one language doesn't work in other languages. The solution is easy -- write the specification in something that doesn't deal with implementation details, and then force the language to implement the given specification.

So, write the WSDL first, then if you want to use some sort of auto-generator, use it to help you set up your functions/methods/subroutines/whatever they're called in the given language.

If you want to know more -- lurk on the SOAPBuilders mailing list for a while, or look for the various SOAP Interop testing, or search for 'SOAP impedence error'