Grandms I have having the same problem with a trojan. I clicked on Mahjongg which I have played for years and Avast tells me I have a trojan. I am also having the problem with other things that I have saved on my PC. Maybe it was the last update. I think I will see if I can uninstall the last update or restore to another date. I can't even research the file, or use the Avast site.

Win32:Delf-MZG [Trj]

Seen this on another site I visit:
"Just saw on the Avast forum that numerous reports are coming in concerning the latest virus definition update: 091203-0 causing what looks like false positives. Occurring now where it is already 12/03/09. If you are running Avast I would recommend that you turn off automatic updates for virus definitions until a resolution is available. Many thing supposedly moved to quarantine making PCs useless.

Turn off auto update by right clicking on blue avast ball.
select Program Settings, Update Basic, then change from auto update to ask

Thanks Genes, I can use my computer but I get false positives every time I scan and sometimes alerts when I open a folder. Most of them are coming from somethings that I have had saved for years, a folder that I call "Fun Stuff". The first one that turned up I deleted and the item would not work then. Now I have to find my Mah Jongg CD and reinstall my game. Grrr...........

Update from that other site
"a new release of virus definitions has been issued to prevent/correct the false positive problem. Should be safe to go back to automatic updates, but make sure you get update 091203-1 or later. For those that may have been victim to this problem, after updating your virus definitions you need to restore items that were moved to the virus chest.

Thanks, Genes. I thought something like this must have happened for both computers to go crazy like this. I have a big job ahead of me since I moved numerous files to the virus chest. I was wondering if somehow my router was causing all this when I turned on the laptop and had the same thing happen.

Well, another update from AVAST! just came in, so hopefully it has corrected the problem. Whew!!!!

Yes, it was kind of weird as this is the first instance in using Avast for a few years. Make sure that its update 091203-1 or newer.
Right click on avast blue ball, select, Start then when grey (dashboard) shows up it should say in the middle panel what the newest update is on your computer

you can also right click on the avast ball select about Avast then in the tree menu click the plus sign in front of VBS it will show you the latest update number.

I was getting them also and knew it had to be false positives since they were things AVAST had scanned previously. So I stopped the scanning and kept checking for the update they would send out to fix it. They are very good about quick fixes.
The bad thing is some people instead of putting into the chest do delete file, that is why it is best to always put in the chest so that should you need it you can retrieve it.

Yes, I do now have that update. I opened the vault and restored all the files I had placed there. Then I ran a thorough scan which found 0 infections.

By the way, when the very first item popped up last night, I sent a false positive notice to AVAST! I'm sure I wasn't the only one.

Now to go through the same procedure on the other computer.