I've heard that Google has a hard time matching ads to content in some cases, but I have a couple of sites now that are really baffling me about how off Google can be, and the kinds of assumptions it can make about relatively common areas.

I have one case where I have a keyword .pro I'm trying to bring up an brand.
It's a common term, not related to cars, but lets just call it "car.pro",

I'm putting up a Joomla site for the domain, and I have the development version coming up under a subdomain with a .htaccess file protecting it. The meta keywords just says "car" (for example),and the meta description is also simple and clearly represents the keywords.

The ads AdSense is putting up have mostly nothing to do with cars! Every now and then I see a 'car' related ad in the lot. Why is that?

In another case (two reg's I picked up last week), I have currently parked with WhyPark.com, running Google ads:

MacBot.net
MacBotNet.com

I've set up the keyword and description on these sites (at least at one point) to both refer to only anti-virus software, and yet no matter what I do, MacNet.com brings up the right ads, but MacNetBot.com brings up stuff related to buying and selling gold and warez and stuff like that, which I don't want on the site.

The only thing that seems to be different is the domain name, and these are hand reg'd, they don't have a history.

Does anyone know what's going on and what I can do about it?