Well, we faced this problem and solved easily. But no lack in support forums.

(on ubuntu and debian derivations)
apt-get install cabextract zoo p7zip arj unzip unrar tnef cpio nomarch

(on RH derivations )
yum install cabextract zoo p7zip arj unzip unrar tnef cpio nomarch (packages could vary)

Perhaps installation process should aware about installing decompressors when installing AV package. :-)