Despite update, antivirus causes Snow Leopard to freeze

Both prior to the Internet Security 4 Mac update and AFTER, whenever I run the antivirus program (I am running Snow Leopard 10.6.2), my computer freezes.  The last three files it froze on were:  PAL_SECAM.icc, wmploc.DLL and 09d3009b29af99e9ac9a...3bae0e35526b4781.cat (do not know the entire file name as that is showed up in the Norton AV window).

 

Is anyone else still having issues, and does anyone have any ideas for fixes?

 

I am pretty frustrated with this whole situation, and am not trusting that the Norton Internet Security 4 Mac is actually functional despite the claimed updates.