Sharing domains objects results in ObjectFactory being overwritten by WSGEN

I have several webservices on different WSDLs, served up using the JSR181 annotations.

I would like to have the different services use and share the common domain objects, that is, objects in the same package.

Using wsgen to generate code, it all works fine, except that when I try to use common domain objects the ObjectFactory class gets overwritten by the last wsgen task that run.

This means that I cannot use common objects in different services, every service must use its own, private objects.

Can this be changed so that the ObjectFactory is added to rather than overwritten? Or is there something else I can do?

Thanks again,
James