Safari is crashed by WDICEngine plug-in

Since I downloaded Norton™ Internet Security For Mac via Comcast in mid 2011, Safari crashes several times a day.  Each time the error message indicates that the WDICEngine plug-in is the cause.  The following is my current configuation:

Mac OS 10.5.8

Safari  5.0.6

in /Library/Application Support/Symantec/WebFraud/WCIDEngine.bundle

is version "WDICEngine 3.1.3f4"