daml+oil.daml problem

Dear Jeremy,
      When I enter the URI:http://www.daml.org/2001/03/daml+oil.daml the parser could not generate a gif.
Why? When I cut the part of daml+oil.daml, e.g. I retain the first 90 rows and the fragment still is well-formed, thus it could generate a gif.
   
thanks for your help.

Wu wenming