This is an excellent example of illegal VRML.  It is an Inventor construct
which allows you to override values in a field.  ivToVRML (in Beta 2
webspace) removes these.
Does this file fail the validator?  It should.
-- 
chris marrin      Silicon      http://www.sgi.com/Products/WebFORCE/WebSpace
(415) 390-5367    Graphics     http://reality.sgi.com/employees/cmarrin/
[email protected]   Inc.         
         "As a general rule, don't solve puzzles that open portals to Hell."