Hi jhiker,
I also question the objectivity of such tests. What would you think that you have two of these tests and Bitdefender in the one test is number one, and in the other test is number final. It says something about the credibility. And then it is what you get out of the virus zoo to test the darned scanners with (in the wild). Furthermore you cannot compare apples with pears (heuristic scanners, the amount of packers detected, on the fly scanning, shortly there are so many features a scanner could have, how do you weigh the results?).
Don't pay too much attention, better put energy into a question how do I achieve the best results on my machine in the way of multilevel-protection.
I think if you have for instance one resident scanner like Avast, together with one non-resident open source solution like ClamWin, some online scanner regularly like BitDefender together with stinger.exe, and the free downloaded DrWebCureIt, together with in-browser script protection and siteadvisor, hyperlink pre-scanning installed, WebShield active, I think in that case we are talking shop, you are well protected, and you need not worry about test results. That is all IMHO.
polonus