Look in your NAV or NIS configuration, delete any rules for "spywareblaster.exe" (there may be more than one) and then either set it to allow again, or just try running SpywareBlaster and updating again.
This seems to be a problem with SpyBlaster V3.3
You can also try to temporarily disable NAV/NIS while updating, OR get the latest full install-file from SpyBlaster and install that manually over your existing one.
Just saw this:
Doubleclick on your Norton Internet Security icon on your desktop and click on "Personal Firewall". Then find the yellow rectangle on the right that says "Configure", click on it. Then you'll get a screen that says in bold text "Program Control". A list of programs will come up with a scroll bar. Scroll down to find SpywareBlaster under the "S"s and with any luck you'll find that SB is shown as "blocked". If that's so, click on it and you should get a miniscreen that should allow you to check "permit" or "permit all". Then close everything and start your internet connection dial-up or broadband. Then open SpywareBlaster. Click "Update", but not the automatic update. You should be okay.