"Malicious Web Site Blocked" returned for Google's cached pages following any/every Google search.

Firefox [v11.0] returns "Malicious Web Site Blocked" for any/every Google cached web page [archived ones located to right of live links] following a Google serach if you use Norton Internet Security [v19.6.2.10] Norton SafeSearch Toolbar [v2012.5.2.6]. According to "Norton Rating" [detailed report] "webcache.googleuserc..." is the culprit in every instance. This started 2 days ago. Before that, never such a problem. Is there a fix?