WARNING: unparseable HTTP header field

["Lucia Di Occhi" <saint_lucy@xxxxxxxxxxx>]

I am getting a lot of the following in my cache.log, as anyone seen it 
before and/or can take a wild guess?

2005/09/11 23:19:36| WARNING: unparseable HTTP header field 
{N*!!!PT!!!U_~~~~~~8OQVn8PP>0!!!NB!!!)2~!!!1t!!!7T!!!<^~!#Ds0*E[XF![(N*!!!PT!!!U_~~~~~~8OQVn8PP>0
!!!NB!!!)<~!!!1t!!!7T!!!<^~!#Ds0*E[XF![(N*!!!PT!!!U_~~~~~~8OQVn8PP>0~!!!)=~!!!1t!!!7T!!!<^~!#Ds0*E[XF![(N*!!!PT!!!U_~~~~~~8OQVn8PP>0~"; 
lf="b!!!!*!!!DJ!!!!$!
!#Eh!!!!$!!#UM!!!!$!!#b'!!!!#!!#b9!!!!$!!#dx!!!!$!!#e7!!!!#"}
2005/09/11 23:22:01| WARNING: unparseable HTTP header field 
{N*!!!PT!!!U_~~~~~~8OQVn8PP>0!!!NB!!!)2~!!!1t!!!7T!!!<^~!#Ds0*E[XF![(N*!!!PT!!!U_~~~~~~8OQVn8PP>0
!!!NB!!!)<~!!!1t!!!7T!!!<^~!#Ds0*E[XF![(N*!!!PT!!!U_~~~~~~8OQVn8PP>0~!!!)=~!!!1t!!!7T!!!<^~!#Ds0*E[XF![(N*!!!PT!!!U_~~~~~~8OQVn8PP>0~"; 
lf="b!!!!*!!!DJ!!!!$!
!#Eh!!!!$!!#UM!!!!$!!#b'!!!!#!!#b9!!!!$!!#dx!!!!$!!#e7!!!!#"}
2005/09/11 23:22:06| WARNING: unparseable HTTP header field 
{N*!!!PT!!!U_~~~~~~8OQVn8PP>0!!!NB!!!)2~!!!1t!!!7T!!!<^~!#Ds0*E[XF![(N*!!!PT!!!U_~~~~~~8OQVn8PP>0
!!!NB!!!)<~!!!1t!!!7T!!!<^~!#Ds0*E[XF![(N*!!!PT!!!U_~~~~~~8OQVn8PP>0~!!!)=~!!!1t!!!7T!!!<^~!#Ds0*E[XF![(N*!!!PT!!!U_~~~~~~8OQVn8PP>0~"; 
lf="b!!!!*!!!DJ!!!!$!
!#Eh!!!!$!!#UM!!!!$!!#b'!!!!#!!#b9!!!!$!!#dx!!!!$!!#e7!!!!#"}
2005/09/11 23:22:21| WARNING: unparseable HTTP header field 
{N*!!!PT!!!U_~~~~~~8OQVn8PP>0!!!NB!!!)2~!!!1t!!!7T!!!<^~!#Ds0*E[XF![(N*!!!PT!!!U_~~~~~~8OQVn8PP>0
!!!NB!!!)<~!!!1t!!!7T!!!<^~!#Ds0*E[XF![(N*!!!PT!!!U_~~~~~~8OQVn8PP>0~!!!)=~!!!1t!!!7T!!!<^~!#Ds0*E[XF![(N*!!!PT!!!U_~~~~~~8OQVn8PP>0~"; 
lf="b!!!!*!!!DJ!!!!$!
!#Eh!!!!$!!#UM!!!!$!!#b'!!!!#!!#b9!!!!$!!#dx!!!!$!!#e7!!!!#"}

I am also getting plenty of this:

2005/09/11 23:37:05| WARNING: unparseable HTTP header field 
{403,14,URL,/vanityParser.cfm}
2005/09/11 23:37:05| WARNING: unparseable HTTP header field 
{404,*,URL,/test.htm}
2005/09/11 23:37:05| WARNING: unparseable HTTP header field 
{500,100,URL,/iisHelp/common/500-100.asp}

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