Adsense 0n Blocked Pages?

I have adsense banners on my site and was wondering if stopping spiders (i.e. Mediapartners) from accessing member profiles and other pages via robots.txt would have an effect on targeted advertising? Do Mediapartners ignore the robots.txt file and check each page showing adsense? If not, how can I change the robots.txt file to allow Mediapartners full access?

Many thanks.
Mike

add this to your robots.txt

Code:

User-agent: Mediapartners-Google
Disallow:

the google bot is seperate from the adsense bot.

Allowing bots but disallowing guests may be considered cloaking. You're best off either removing Adsense from those pages or letting it display PSA's or generally generic to your website type advertising that Adsense often does when it can't crawl a page.

that's not cloaking....

cloaking is DISPLAYING different CONTENT to bots vs humans.

robots.txt has no bearing on content display.

I see no issue in this at all, as like i said before, the adsense bot is an entirely different crawler from googlebot.