Avast scanning problem?

Avast Free Antivirus / Premium Security
1

Avast found another Evo-gen false positive. I’ve gotten used to that. But this time it deleted the file and did not move it to the Virus Chest. That was really annoying, not able to recover the file for more thorough testing. So I dug out the CD it came from (which was published in 2001) and scanned the original file. It scanned clean, so I tried to copy it to my hard disk, and then Avast reported the suspected virus and would not copy the file.

So I see three problems. In order of increasing severity (in my opinion):
(1) The number of false positives of the Win32:Evo-gen [Susp]. I’ve posed about this before., but I understand that detection algorithms can not be perfect.
(2) A file with a suspected infection being deleted and not moved to the virus chest.
(3) A file that scans clean with an explicit Avast scan (from Windows Explorer menu) but then gets a reported suspected virus when I try copy it or try to run it. What could you possibly detect during a file copy that you could not detect during an explicit scan?

2

Win32:Evo-gen [Susp] = suspicious is a on access detection only, it will not show in any scan
New Toy in the Avast Research Lab https://blog.avast.com/2012/12/03/new-toy-research-lab/

but yes i agree, they should do like Norton/Symantec and only give a suspicious warning and a user option what to do

as i understand Norton/Symantec use a system that monitor the file and check it with some cloud database, so if later found malicious detection is added or if not suspicious warning is removed