I should be more exhaustive. ;-)  It appears to be only
the Mac version of IE 4.0 that doesn't like the ':'. 
Wacky. Does the spec say anything about that? 
-steve
>>>>> "Steve" == Steve Spicklemire <steve> writes:
    Steve> IE doesn't like the 'HTTP/None: 401' it wants "HTTP/None
    Steve> 401 ..."  ^