Many advertisers have been complaining about the accuracy of the Google Keyword Tool. We have complaints specific to the counts showing different results based on being logged in or out.

But now we have a Google AdWords Help thread with confirmation from a Googler about at least one or two keywords being reported inaccurately.

The advertiser said:

Google Keyword Tool Engineer, Scott, said:

So Google is now admitting to an issue so maybe other issues will be found when they debug this?

Forum discussion at Google AdWords Help.