deny_info not working as expected.

[Sherwood Botsford <sbotsford@xxxxxxxxxx>]

#Block MS Internet explorer
acl browsers.bad  browser "/etc/squid/browsers.bad"
http_access deny browsers.bad lab
http_access deny browsers.bad laptops
deny_info ERR_NOEXPLORER browsers.bad



Now if I use MSIE to access a page, I don't get this error page, 
but rather get a generic page.
I've obviously missed a detail somewhere.