Attempt to accesse non-existent property

In Services 3, D6, if you have at least one endpoint and flush caches, line 136 of services.module will attempt to access a 'disabled' property of the endpoint. Unfortunately the endpoints have just been loaded with ctools_export_load_object, and the schema there has no such property. The end result is an error message on the screen.

I have added property_exists() call to check for this condition, and not attempt to access the disabled property on the endpoint object when such property does not exist.

You, experienced services developer, I rely on to tell me if I have done the correct thing, or if the schema should be expanded to actually have a 'disabled' property.