xml:base attributes and Schema Validation

Hello,

I'm implementing an XInclude processor, and one of my goals is to make the
processing transparent to the Schema validator, if the XInclude processing
is performed before the validation.

However, in section 4.5.5 of the spec, it is specified that xml:base
attributes are added to the top level included items, if the [base URI] is
different than the include parent's [base URI]. This creates problems with
schema validation, unless the xml:base attribute is specifically allowed in
the schema, which interferes with the transparency of the XInclude
processor.

I'm wondering if anyone else has encountered this problem, and in hearing
any approaches they had to solving it.

Thank you,
Peter McCracken
IBM Toronto Lab