Thanks for your replies.

This thread was to report the problem I am running into.

It is of course normal to see programs starting various order at boot time, but it would be nice to solve the root cause of the race condition that causes startup to hang.

I did not experienced it with previous version of Avast… perhaps I was lucky… is this a v4.5 issue only ???

Anyway, as I said, I already plan to work-around this issue by means of serializing the starting of startup applications…