You still don't have beta build installed... beta release should fix all your problems if you are willing to install it. Anyway, this is the last beta release before Alwil team releases final version duuring today... however, you shouldn't be affraid, and you should proceed with installation of beta 4.5 Build 536 'cause it's working flawlesly...
What is the version that you currently have installed ? Go to avast! blue ball icon in the system tray, right-click it (right mouse button, not left) and choose about avast!...
What does it say under Build: field ?