Another Update problem- 54GB in my VirusDefs folder

Windows XPPro running Systemworks. Icon showed need to update virus definitions. Did so. Icon did not change. Long story short. Last Update is shown as June 30, 2012, and between then and today,  I reset the system clock three times and tried repeatedly to update the definitions. Result is that the folder \Common\Symantec shared\VirusDefs is now 54GB in size - -you read it correctly, 54 Gigabytes. It appears that each time you update the definitions four *.temp files are created in the \ VirusDef folder. There are more than 178 *.temp folders in the folder on my computer. Still haven't worked it out . Any help out there??

Curtis