Word 2003 custom schema limitations

Hi All,

TPTB have asked me to investigate the use of Word for lightweight editing 
of XML documents (don't laugh!).  So, I got our custom DTD converted to a 
schema and successfully added it to the template library.  When I try to 
create a new document using the schema, I get the following error message:

The XML schema cannot be used because it has more than 256 levels of 
hierarchy.

I have looked all over microsoft.com and used Google, but I can't find any 
references to custom schema limitations in Word 2003.

Has anyone seen this problem?  Does anyone know of a way to work around it 
(other than the obvious, which is "Don't use Word"!).

Thanks

Nadia