FULL PRODUCT VERSION :
Java Version 6 Update 5 build 1.6.0_05-b13

FULL OS VERSION :
MS Vista Home Premium SP1 32bit

BROWSER VERSION:
Firefox 2.0.0.14

How to reproduce (Based on user submission):

1) Download and Install JRE 6u05b13 (latest version available) from java.com
2) The system tray icon (Java) popped up with the message "Update Available". Clicked on same, launched another message "you already have latest version installed".
This behavior is appearing repeatedly
Note: Switch off update service to stop update bubble popping up