#2 xsd substitution groups

[Rob]

I am trying to edit instance documents using an XML
schema that uses substitution groups. When I try and
load the document I get errors:

Error creating schema.
...
MSV warning: "anyType" is implicitly used as the
content model of this element. Is this your intention?
If so, please consider to write it explicitly as
type="anyType".
MSV error: Unimplemented feature: "omitting type
attribute in <element> element with substitutionGroup
attribute"

So I think this is due to a limitation of Sun's Multi
Schema Validator.

The pollo website states "Pollo allows new schema
implementations to be plugged in". Is this something
that can be used to solve my problem? I know Xerces
2.5 supports substition groups. How could I make use
of this?

Generally, I find pollo much easier to use than any
other xml editor I have tried - good work...