Service endpoint not found

[Jack Sprat]

I know I've run in to this problem before but cannot recall the cause of it.  I 
have an Axis 1.6.1 service deployed.  When a request is made to the simple echo 
operation I get the following error:
The service cannot be found for the endpoint reference (EPR) 
http://mydomain.com/svcname/services/MyService
It looks like the service cannot find the WSDL.  What would cause this error?
Thanks,T