There seems to be an issue with Squid3:
Crash report begins. Anonymous machine information:
FreeBSD 8.3-RELEASE-p4 #1: Sun Sep 9 22:25:39 EDT 2012 root@snapshots-8_3-amd64.builders.pfsense.org:/usr/obj./usr/pfSensesrc/src/sys/pfSense_SMP.8
Crash report details:
[10-Sep-2012 06:03:16 UTC] PHP Fatal error: require_once(): Failed opening required 'squid.inc' (include_path='.:/etc/inc:/usr/local/www:/usr/local/captiveportal:/usr/local/pkg') in /usr/local/pkg/lightsquid.inc on line 36
Moved this to its own thread, as that is a PHP coding issue in a package, not something to do with a 2.1-specific binary issue.
Sorry rcfa, I saw it only today.
Try to clear crash report/php error, check and save squid gui tabs before testing again.