[Zope] REQUEST_METHOD 'LOCK' 'LOCK'

When downloading a word off a zope server using IE, the REQUEST object shows the REQUEST_METHOD as 'LOCK'. Does anyone know what this means? I get a network login prompt in windows when I try download this file. I can just cancel through it, and I get the file fine. Is the REQUEST_METHOD set to 'LOCK' related? How/where would the REQUEST_METHOD be set when downloading a file Thanks, Mark