I usually prevaricate about updating, then go ahead and do it, then regret it.
It's nearly always the same problem - I finish up with two versions of the redirect driver (aswRdr ans aswRdr2).
Webshield and mailshield both stop scanning (they both say they are working, they just never scan anything). I then have to do an uninstall fresh install from scratch to fix the problem.
This only appears to affect some W7 64bit systems, and, disappointingly, it's been going on for ages.