Can not upgrade clamav

[Andras Galos <galosa@netinform.hu>]

Hi,

I see clamav 0.91.1-1~bpo.2 at 
http://backports.org/debian/pool/main/c/clamav/, but can not upgrade my 
0.90.1-3etch4 packages to the new one.

If I run `aptitude upgrade -t etch-backports clamav` only clamav-base 
and clamav-testfiles would upgrade.

How could I upgrade all my clamav packages to the current 0.91.1 version?

My sources.list file contains:
deb http://ftp.hu.debian.org/debian stable main contrib non-free
deb http://security.debian.org/ stable/updates main contrib non-free
deb http://www.backports.org/debian etch-backports main contrib non-free

My preferences file contains among others:
Package: clamav
Pin: release a=etch-backports
Pin-Priority: 999

The result is the same when my preferences file contains the above 
pinning for all of clamav's binary packages like libclamav2, 
clamav-base, clamav-freshclam, etc.


Best regards,
Andras Galos