Qistina,
I agree with you 100%. There is no legit reason for such an annoying "alert" constantly popping up (and no way to disable it, except for the hack mentioned in this thread). At work, we were told to remove Avast! from work computers because of this problem. The alert came up at several "inconvenient" times, and two specifically caused the higher-ups to demand its removal: 1) During a presentation (which was being webcast to many remote locations), annoying to say the least. 2) During the monitoring of a live video-feed for medical research - this blocking of the screen by the update warning potentially could have resulted in injury to the patient being observed. Fortunately, it did not result in any injury, however it did cause some loss of data of the procedure while it was being recorded. This was the proverbial straw that resulted in the order to remove the software from all work machines.
If the purpose of such an alert is to make sure the user is protected, then why not simply cause the alert to be displayed each time the user asks to update the iAVS database? That is a logical time for the user to be notified, and it's appearance is able to be controlled by the user. Even when we had Avast! v4 installed on the work machines, we did not enable automatic updates, because we wanted to control which programs were running during critical operations. If we had gotten warnings about the new program version every time we did a manual iAVS update, it would have achieved the same purpose, been under our control, and also not have been dangerous, nor even that annoying.
I like and use Avast! (now only at home), but the uncontrollable notices about the new version were enough to cause our department to switch to another program. Maybe we have less protection, but at least we don't have to risk potential problems cause by such notices.