Squid / LDAP authentication working but having trouble with aptitude blocked by proxy

[David Goldstrom <goldstrom@yahoo.com>]

Hi all,
  I have authentication (exactly as in the debian edu wiki) working well, but to run updates I have to stop squid and restart with the old configuration file, then restart with the current squid.conf. I've tried several different ways to get apt-get to go through squid, including additional acl's in squid. No luck there; Setting environmental variables for bash looks promising, but I don't seem to have it quite right. 
Can anyone tell me how to either have aptitude bypass the proxy or authenticate (perhaps by setting the http_proxy = username:password@tjener.internal:3128)
Thanks,
David