Taking on the suggestions from the forum members that 1456 is working well , I installed that. But seems like in my system flash and Avast would not work together ,making Firefox hang everytime whenever I click a Noscript (Addon) place holder over a flash screen. .As suggested by someone earlier I removed the entries related to AVAST from my firewall to build the details fresh, Still nothing.I tried disabling Web guard , mail guard one by one to check , but each time it hanged. I disabled Avast shields control for a few minutes and then everything worked well.
So went ahead and installed 1426. While installing it never gave a clue that it is installing 1456. But now my summary screen looks otherwise. Strangely now flash works well with all shields enabled. But the Virus definition version is always RED and even on pressing the Update button nothing much seems to open except for some progress bar and total time like 4s or 5s. Clicking on the summary very much shows the same picture.