Java not working after software update. Any ideas?

Running a 2011 intel imac, OS 10.6.8. I've just used software update, part of which was the latest java update from Apple.

Now when I visit some favourite online gaming sites, the games fail to load (they were fine before). I get a dark screen, and on some of the sites a 'plug in failed' message. This happens in safari and firefox. I've played with java preference settings and it makes no difference.

Just wondering if anyone has had anything similar, knows of a fix, or how to unistall the java update and go back to how it was before.

Many thanks.