Script Shield doesn't support Opera, so if that's what you are using, then yes, it doesn't work.
Apart from that, I'm using Opera on all my computers and never had a single problem with WebShield. So, if you have a particular page and a more comprehensive description of the problem than "played silly buggers", you're certainly welcome.
Btw, what exactly did you set in the custom install, compared to the one you had before?
Script shield doesn't work for me on either of my 64bit machines using any browser.
Sites affected by Webshield? Avast Forum, vbulletin.com vbulletin.org, BBC.co.uk just to name a few. Select these from a bookmark or speeddial and 90% of the time they simply do not begin to load for anything up to 20 seconds, avast's orange globe remains still. I often have to reclick the bookmarks several times, disable avast and restart without avast loaded and no such issue ever occurs.
The new beta only offers an install not an upgrade ,
I selected custom install without the following :
No Safe Zone,Web Rep, Virtualisation,Gadget,Script Shield,Behaviour Shield.
All features loaded, all previous settings are gone.
The uninstaller didn't run either on the first 2 attempts.
And why oh why have you added yet more spam on the GUI of a paid application? Really not acceptable.