diff --git a/Plugin/CTFWhitelist.m b/Plugin/CTFWhitelist.m
index b69b7a7b..d6029e96 100644
--- a/Plugin/CTFWhitelist.m
+++ b/Plugin/CTFWhitelist.m
@@ -152,9 +152,12 @@ - (void) _addToWhitelistAlertDidEnd: (NSAlert *)alert returnCode: (int)returnCod
 
 - (BOOL) _isHostWhitelisted
 {
-	// Nil hosts whitelisted by default (e.g. Dashboard)
-	if (![self host])
-	{
+	if ( [[self baseURL] hasPrefix:@"about:"] ) {
+		// encountered an ad on addictinggames.com where it loaded an
+		// about:blank page and then inserted ads there
+		return NO;
+	} else if ( ![self host] ) {
+		// Nil hosts whitelisted by default (e.g. Dashboard)
 		return YES;
 	}
 	
diff --git a/Plugin/Plugin.m b/Plugin/Plugin.m
index c3b90c9f..89501030 100755
--- a/Plugin/Plugin.m
+++ b/Plugin/Plugin.m
@@ -704,10 +704,18 @@ - (BOOL) validateMenuItem: (NSMenuItem *)menuItem
     SEL action = [menuItem action];
     if (action == @selector(addToWhitelist:))
     {
-        NSString* title = [NSString stringWithFormat:
-                NSLocalizedString(@"Add %@ to Whitelist", @"Add <sitename> to Whitelist menu title"), 
-                [self host]];
-        [menuItem setTitle: title];
+		if ([self host]) {
+			NSString* title = [NSString stringWithFormat:
+							   NSLocalizedString(@"Add %@ to Whitelist", @"Add <sitename> to Whitelist menu title"), 
+							   [self host]];
+			[menuItem setTitle: title];
+		} else {
+			// this case happens sometimes if the base URL is "about:blank",
+			// so there's no base URL to use for the whitelist, so just disable
+			// the menu item
+			enabled = NO;
+		}
+       
         if ([self _isHostWhitelisted])
             enabled = NO;
     }