I am having issues with a custom scan I run nightly with 6.0.1289 Free on Win 7 64 bit. If I have it scan the memory it seems to lock up at least 900Mb of RAM and doesn’t release it until I reboot.
I think pk could help you with Poolmon.
http://support.microsoft.com/kb/177415
http://forum.avast.com/index.php?action=profile;u=231715
do not use the “scan memory” setting as it often give some strange scan results
if you search the forum you find lots of cases
i recomend using the default scan settings
there is a file shield running in the background at all time…so why scan every night
Don’t scan the memory…!! 
No need for Poolmon… I would guess it’s just a misinterpretation of something.
How exactly do you “measure” the unreleased memory?
Sure enough, after further research it looks like running the memory scan is a shaky idea at best ;D I think I’ll take everyone’s advise and disable the feature. I’m willing to give Poolmon a try if if will help improve the product though.
@Pondus Why not scan every night, unused CPU cycles are a waste? I run twice daily incremental backups and in the event of a file shield detecting an infection I like to look at the last full, detailed scan to see that there is a low likelihood of there being anything else on the machine.
@igor I recently switched to Avast from MSE after testing the on-demand abilities and the interface and liking what I saw. I installed it on my two 2 PCs running the same OS, although I had configured Avast differently. Afterwards I noticed the free memory was much less in the mornings than afterwards on one of them. I use Zabbix to monitor my network so I looked at the free memory graphs and noticed the one machine that the memory dropped sharply precisely the same time Avast started scanning and only slightly came back after the scan stopped. I played with settings and figured out it was the memory scan.
Good. 
@Pondus Why not scan every night, unused CPU cycles are a waste? I run twice daily incremental backups and in the event of a file shield detecting an infection I like to look at the last full, detailed scan to see that there is a low likelihood of there being anything else on the machine.when/if the file shield detect something, then you can do a quick/full scan....not necesarry to do it every night
The point is that when something is detected I want a full scan to have already been done so I know that the image I’m restoring too is most likely clean. These PCs run 24/7 and there is no problem doing a nightly scan at 2AM when no one will be using them. Is there any reason why I shouldn’t do a nightly scan?
I’m certainly not familiar with Zabbix, but the memory scan basically forces Windows to load all the data it may have put aside into the swap file back - so it may look as a change in “free memory” in some tools.
However, I don’t really think there’s any memory leak there.
Zabbix is a network monitoring platform, similar to Cactai, Nagios or Orion. I suppose, given your explanation of the scan and my lack of knowledge of Win 7 memory management, that this could just be cached memory sitting around waiting for something better to do.