Test the version:
Java Version Test
BTW, the current update is 6 Update 20
Also, you can remove older versions as they are not automatically removed and can represent a security risk. I use JavaRa
JavaRa
Also suggest Secunia Personal Software Inspector (PSI) to test for insecure programs and addons
PSI
You will find some browsers insecure, if yours are up to date, it usually means the company hasn't addressed the vulnerabilities yet.
A Guy