Windows vs. Mac vs. Linux - Which is more secure?

According to a report released by Jeff Jones, the security strategy director in Microsoft's Trustworthy Computing Group, if you look at the number of publicly disclosed security vulnerabilities during the first 90 days of availability, Windows Vista turned out to be more secure than Windows XP, Red Hat Enterprise Linux 4 Workstation, Ubuntu 6.06 LTS, Ubuntu 6.06 LTS - Reduced Component Set, Novell SUSE Linux Enterprise Desktop 10.8, Novell SLED 10 - Reduced Component Set and Mac OS X v10.4.

Here's the graph that basically summarizes the report:

I've been through the report [PDF] and I can't see any kind of underhanded tweaking of the numbers to make Windows Vista come out as the most secure OS in the list.  I also can't see any tweaking that makes the other operating systems seem less favorable.  So I'm left with a couple of questions that need answering:

Question #1: Is Windows Vista really more secure than Mac and Linux platforms?

Question #2: If, despite reading the report, you're still convinced that a Mac or Linux platform is more secure than Windows Vista, how do you bend your "reality" around this report?

Go!

[Updated: June 22, 2007 @ 6.40 am] - Many of you seem to have misread what I wrote and think that I'm agreeing with the conclusions of the report.  Nowhere have I said that.  Don't shoot the messenger.

[Updated: June 22, 2007 @ 6.47 am] - Looks like we killed the TalkBack server.