AVG Heavy Disc Access

[#1]

Around 30 minutes ago I noticed all my hard drives going into a frenzy of activity.
A google search indicated an issue with avgchsv.exe.
When I End Process all disc activity stops but it returns within seconds.
It seems many people's systems are slowed to a crawl but my quad core is coping OK but I'm not happy with this constant disc access. Apparently it's an optimisation scan.
I uninstalled AVG, rebooted and re-installed the latest version and do not hav Link Scanner installed and ensured that the Optimisation scan was not selected. Yet, as soon as AVG finished installing it continued with the disc access (9 discs whirring away at once makes quite a racket). it taks between 8 & 12% of CPU resoource and three of the four cores show more usage.
Has anyone else found a way to stop this (other than changing to another AV program)?
Do I just have to put up with this while it 'optimises' - how long with 4TB take?
On an initial Google search I found things like avgforums and Yahoo Answers but they didn't really offer a solution.

[#2]

Hi Mav,
I've ditched AVG following the move to 9, I was finding it doing the same thing 😕 I solved it by moving to avast and have had no problems since. Tried avira but the nag screens really annoyed me, stealing focus even from fullscreen games, I know you can remove execute permissions from avnotify but to have to do that after every update was very irritating. Also it continually warned me I hadn't updated my database in over 7 days, even though I was doing!
Apologies if that's not what you wanted, but for me it was an ideal solution.

[#3]

it only optimizes once just after install of AVG9 and builds a database that it doesnt check files on it.
if it is not the inital scan, is it the link scanner on browsing, if so switch that dam thing off from the control panel, not only does it slow up browsing, but it also mucks up Google stats

[#4]

I fell asleep soon after my initial message and only two discs at that time seemed to be whirring incessantly.
Now it's all quiet again.
@Matt
I did try Avast a few years ago but didn't like it. Can't remember why, now.
@pierre
What I didn't mention was the above didn't happen after an install but suddenly and for no apparent reason. AVG had been installed and regularly updating itself since I installed W7 many weeks ago. I seem to remember selecting the Optimisation option at that point.
I found out about Link Scanner a long time ago and never even installed it under AVG9.

[#5]

how often is it set to do a full system scan?  From AVG control, left hand Computer scanner, then Manage scan, the default is ridiculously often, I set mine to lunchtime on Saturday, dont even know why, but on my wifes netbook it did find ADT cookies and killed them

[#6]

I did leave it set for some ridiculous time like 4pm on a Wednesday. Can't be too sure a I have since re-installed.
I've curreently set it to Mon, Wed & Fri at 02:00

[#7]

I have been using avast! now for ages and have moved a number of my friends over to it. It seems to use far less resources than AVG and works very well.