throw new SoapException: SOAP Fault has Stack Trace in faultString element!

[John Saunders]

I'm in the final stages of developing a web service. One odd thing I'm
seeing is different between our test environments, running Windows Server
2003, and our development environment, running Windows XP Professional: even
if ex.Message contains "This is a message", when I throw ex (ex being a
SoapException I just created), I get the entire stack trace in the
<faultString> element! I'd prefer that my customers not see this! On my
development machine, it works as expected. Only the Message property
displays.

I have confirmed that ex.Message really does contain only the message text
just before I throw it.

Any ideas on what could be causing this? Or, is there any other way to
return a SOAP Fault other than throwing a SoapException or
SoapHeaderException?

Thanks,
John