Apple's new version of Mac OS X 10.7 modified a bit the implementation of the Java runtime environment. This change can affect your online browsing when accessing different banking sites or other Java based online applets.
If you are in this situation, just follow these instructions:
1. Close the Internet browser.
2. In the search box Spotlight in the upper right corner, type Preferences Java and run it:
PS: if you have updated to Java 2012-006 and you cannot find "Java Preferences", check this out!
3. On General tab check "Enable applet plug-in and Web Start applications":
4. in Network Tab press on "Delete files..." and confirm OK .
Done! Now you can start your Web browser and do your thing!