squid denies access to ftp and gopher objects

Hello,

I am running squid-1.NOVM.10, in squid.conf I have something like:

acl A-src 10.0.0.0/255.0.0.0
acl A-dst 10.0.0.0/255.0.0.0
acl B-src 172.16.1.1 192.168.10.3

http_access allow A-src
http_access allow B-src
http_access allow A-dst
http_access deny all

icp_access allow A-src
icp_access allow B-src
icp_access allow A-dst
icp_access deny all

However, I can read the following on the access log file:

863613021.487 28 192.168.10.3 UDP_HIT/000 51 ICP_QUERY ftp://software.watson.ibm.com/ - NONE/- -
863613021.847 96 192.168.10.3 TCP_DENIED/000 510 GET ftp://software.watson.ibm.com/ - NONE/- -

This only (but then always) happen for ftp and gopher objects.
What did I miss ?

--
Marc Roger