squid + snmp + mrtg-2.7.0

Good Day All

Running FreeBSD 2.2.8, Squid 2.1Patch2, MRTG-2.7.0

I'm new at snmp and squid. I'm trying to get statistics with the snmp
interface of squid.
I think I have squid configured Ok. When I start it I get the following:
Accepting SNMP messages on port 3401, FD 43.

And if I do
 snmpwalk -p 3401 localhost public .1.3.6.1.4.1.3495.1.1
I get:

enterprises.3495.1.1.1.0 = 16764928
enterprises.3495.1.1.2.0 = 922176
enterprises.3495.1.1.3.0 = Timeticks: (41948118) 1 days, 20:31:21

I have created a squid.cfg file, when I run mrtg all goes through OK but my
graphs don't show any data.

However i have found that after a while some graphs will display data and
then nothing will be displayed again.

Attached find a copy of my squid.conf file.

Many thanks for your help/suggestions.

Craig

 <<sample-mrtg.conf.txt>>