"Cannot send to Chest" message

[Jima]

The second time I opened a game someone sent me, I got an avast! virus warning and a recommendation to send it to the Chest. 
Several attempts to do so all resulted a a message somewhat like "the operation could not be accompmished since the system is in use."   Sorry I can't remember it better.
I ended up deleting it and went about my business, but decided to do my weekly scan a day early.
There were three nearly identical warnings and all went meekly into the Chest.
What action would have done this in the first place?
I very rarely get warnings in real time or on a scan (knock wood).
Thanks 

[DavidR]

What is the infected file name, where was it found e.g. (C:\windows\system32\infected-file-name.xxx) ? 
Check the avast! Log Viewer (right click the avast 'a' icon), Warning section, this contains information on all avast detections. C:\Program Files\Alwil Software\Avast4\ashLogV.exe
 
- Or check the source file using notepad C:\Program Files\Alwil Software\Avast4\DATA\log\Warning.log and copy and paste the entry.

If you have Win2k, XP, vista or Win7 (all 32bit), you could enable a boot time scan. Right click the avast icon, select Start avast! Antivirus, a memory scan will take place followed by the opening of the Simple User Interface, Menu, 'Schedule boot-time scan...' Or see http://www.digitalred.com/avast-boot-time.php. Don't opt for deletion (you have no options left), always send to the chest and investigate.
 
Look in the C:\Program Files\Alwil Software\Avast4\DATA\report\aswBoot.txt file, check this file using notepad and copy and past the info on the detection.
Or use a command line, Windows, Start, Run and type, C:\Program Files\ALWIL Software\Avast4\sched.exe /A:*

[Jima]

Thanks for the help.
It looks like the problems were "Sign of JS Fake AV CH and CL (trj)"  and "Sign of JS redirector AM (Trj)"
They were in "C:/docu...." but the rest is hidden.
They were on the Warning list as "System" on the day I couldn't send them to the Chest and as "Owner" after the scan.
I am pretty sure they went to the Chest the second time but can't find that log.  Do I need to reopen the scan function to find it.
As I said, I am mainly interested in how to have gotten them to the Chest the first time.

[DavidR]

By checking the source file directly as I mentioned will display the full details:

- Or check the source file using notepad C:\Program Files\Alwil Software\Avast4\DATA\log\Warning.log and copy and paste the entry.

You use windows explorer and navigate to the location of the source file, above (if it is in the avast log viewer the file must exist as that is where it gets the information from) and use notepad to open it.

I can't answer your question because I don't have the information to say why for sure, but files in use may be blocked by windows and that is why I gave the suggestion of a boot-time scan as that happens before windows is fully loaded so the offending file wouldn't be in use.