Can't import NIST UnitsML XSD Schema

[lkiff]

I'm not an XML guru, so I'm frustrated that an XSD schema, built with an Altova tool, on a project sponsored by NIST, fails to load due to a namespace error:

'The namespace prefix is not allowed to start with the reserved string "xml."'

Can someone help me to figure out what I can do to fix this so I can import this schema?  
http://unitsml.nist.gov/Schema/unitsmlSchema-0.9.18.xsd

[lkiff]

Since I'm not a patient person, I managed to find the solution before I found help.

The declaration that prevented the schema from loading is:
      xmlns:xml="http://www.w3.org/XML/1998/namespace"

When I removed this from the UnitsML xsd, it imported properly.

[«Midnight»]

Does Altova gracefully accept removal of this declaration? Or does it issue a nag, or worse yet does it insist on inserting the declaration on a round trip of the file?