kernel32.dll wsock32.dll winsock.dll in virus chest?

I recently updated my Avast 4.8 free edition to 5.0 free, and the new UI improved a lot :-),But I also found a problem that when i checked the files in the virus chest, some Windows systems files such as kernel32.dll wsock32.dll winsock.dll were in there,and the scan of these files indicated no virus at all. I was using Avast 4.8 when these files were moved into the virus chest but no notice had ever been seen. Why were these clean system files in the virus chest then? Is it a bug of Avast 4.8 free edition? Thanks for any information.

Way back they were put to the chest for security/backup reasons (by v4).
If you update to 5.0.507 they will be automatically removed from the chest.
asyn

Don’t worry deleting them within Chest… I never saw an use for that “backup” files really…