I've had the same problem too with AVG 7.5.
I have noticed it tries to download updates as the computer comes on, i realise this is because AVG is one of the first programs to load up ( anyone that had AVG on win98 will have noticed this because AVG does a boot sector check as the computer starts, this is not shown with XP and Vista because of the start up screen )and if it's set for automatic updates it tries to do so as soon as it starts, this does cause a problem because connection to the net is usually one of the last things to load.
Should i get this happening, i just wait till the computer has fully finished starting, then double click on the AVG control icon in the task bar and manually check for up-dates.