Hi,
Sometimes, when you manually update the Program (by right-clicking on tray icon), Avast update just hangs (I attach the screenshot of when hanging), it doesn't start nor stop the update, and it doesn't even show a 'Cancel' button, so while in this state you're not able anymore to manually update (when right-clicking in tray, Update options become gray), unless you restart the computer.
I have up-to-date system (Avast 7.0.1473 with definitions 121029-0 on Win7 SP1). This issue is happening now but was also in previous versions.
The reason for this issue might be a conflict between manual and automatic updates (if automatic one is already running in the background or it is about to start, then maybe the 'overlapping' manual one gets stucked), because it happens especially right after turning on the computer, when Avast is most likely doing its first automatic update check.
This issue, besides annoying (no manual update and the need to restart), may be dangerous since not sure if during the 'hang' period the automatic updates are performed or not.