Squid blocks everything

Hi,
Here is the situation:
Whenever I change anything in Squid.conf, Squid seems to block everything.
 
Initially I was working in the ACL rules and if I add or delete entries from the
files of banned sites, or add a new file, or a new acl then squid blocks.

So I changed the debug level in Squid.conf to see if it told me anything
interesting and the same thing happened.

My students are starting to run out of banned sites or new webmail
addresses but there are still some I need to add.

I have read the FAQ, the whole thing is printed on the desk in front of me as
well as the release notes and can't find anything relevant.

Is there a maximum number of ACL rules I should use?
Is there a maximum number of entries I should put in a regex or other acl file?
Is it better to run an external redirector program?

I am running Squid 1.1 on RH4.2 (both to be upgraded, as soon as I have a
machine available)

Should I just live with the problem until I can upgrade?
Should I just shutup? :-)

Any clues, advice, other places to look or docs to read appreciated.

--
Simon Bryan                    sbryan@olmc.nsw.edu.au
Information Technology Manager sbryan@mpx.com.au
OLMC Parramatta