probably false positive

I am using avast!4.6.652 home edition.
I’ve just updated the VPS file to 0519-2; I’ve scanned my pc and avast has found the file:
C:\Programmi\Shareaza\Plugins\ImageViewer.dll
infected by:
Win32:Puper-F[Trj].
I have moved/renamed this file, but I thought this was a false positive: in fact I’ve scanned the file at the on-line kaspersky scanner and it resulted clean.
I use Shareaza and unless this file I can’t display the preview of images I download.
What have I to do?

Read what Igor said in here:

http://forum.avast.com/index.php?topic=13433.msg113573#msg113573

… and do exactly as he mentioned in his reply.

Cheers !