Am also getting this Information message out too:

Security Error: Content at http://googleads.g.doubleclick.net/ may not load data from <another of my sites>

I using Firefox 3.5, I wonder if it's anything to do with that. I don't see to have errors in other browsers.

I see them too in Firefox too, I believe anyone who looks at a site with adsense on it using Firefox would.

It is interesting to note that even though the report itself is worded "Security Error" (my emphasis), if you're looking at the Firefox Error Console, these notifications show in the "Messages" tab, and not the "Errors" tab, so they're not really errors.

Also, unless I'm mistaken, these notifications only show if you are looking at the Firefox Error Console, so ordinary users would never see them.

I see them too in Firefox too, I believe anyone who looks at a site with adsense on it using Firefox would.

I've just gone all over my sites with Firefox and haven't seen it once. Maybe it is the version of code that you may be using that causes it.

Are you seeing this with the new code ? [I use old code].

@fredw:
The first output I posted is in the 'Errors' tab. And the user sees the error via the red exclamation mark that appears in place of the green tick/check.

The second output I posted is in the 'Messages' tab.

[edited by: davelms at 8:53 am (utc) on June 28, 2009]

@Lame_Wolf:
I've seen it across a number of my sites, some of which I haven't updated in quite a while. However, I believe I am using the latest code in all of them.

Update:
I have noticed that I don't seem to get the errors when a Text Ad is being shown. It certainly seems to be with the Image Ads only. A quick search of the messages above in Google and on Google Help forums would suggest others are having similar problems. I think my main concern is what code is not being executed after the javascript error and will it affect click tracking?

I have all text ads and all new code. But I also use Google analytics. Perhaps that is a factor.

Re: Location.toString error: I've seen this on other sites caused by things other than adsense. I've seen YUI (Yahoo JS library) cause this "error" too, for example. It's my understanding everyone ignores it because there are no negative effects to the browsing experience because of it. And, IE users would never see the errors unless they have "show JS errors" turned on in their browsers, which is off by default.

I was posting here more because I was wary of what logic from within the Adsense javascript code may not be getting run because of the error. Rather than because I was concerned re: user experience. I agree there is no issue with user experience. My sites are just as poor with or without this fault ;)

i.e. I was worried in case the next line of code after the error, the code that isn't getting run, may have some important publisher tracking code on it that means I won't get credit for any clicks, for example ... the failing code is not within a try/catch block (else we wouldn't have seen the error) and Firefox has terminated the running of the Adsense code block at that stage.

So should I be worried about what lines of code aren't getting run and should I pull Image Ads until it gets fixed?

{that's just me thinking out loud, I'm not really asking for someone to run my life for me ;) }

fyi, I also use Google Analytics.

It's definitely a new problem. Now does it coincide with my installing Firefox 3.5 (could the bug be with Firefox for example?) or is it down to a new code release of Adsense logics. They're what I'm currently pondering. I'm going to do some trials with Firefox 3.0 because I'm sure I never saw these errors with that version installed.

Well, seems it happens with Firefox 3.0 as well.

Maybe I just never noticed it before. Unless anyone panics me with a reply, I'll not worry about this particular error any more.

This is not a new error. A casual googling of the error shows it goes back to, at least, Feburary.