"TCP_NEGATIVE_HIT/404 615 GET" for file that does exist

["Gregory Machin" <gregory.machin@xxxxxxxxx>]

Hi
There is a file I'm trying to download via my proxy, but cant ...
squid loggs show

1191409989.051      0 192.168.2.203 TCP_NEGATIVE_HIT/404 615 GET
http://www.coltech.co.za/pnp/files/vPbPsCrVJ/SFUP-V447B4-D.zip greg
NONE/- text/html

If i bypass the proxy I can download the file fine ... what would be
causing this ?

Greg