Like before here's some results of running BitDefender, ClamAV and F-prot on over 11K of files containing Rootkits, LKM's and other goodies. Because of what I do most of the files are GNU/Linux related. (I run AV like a pentester would run metasploit against a networked entity.) I'm well aware of the AV-on-GNU/Linux-yes-or-no debate and this is not the place to go into that: search LQ or open up a thread if you need to discuss validity.
The commercial AV market is kind of an odd...