i've got this problem as well. i've noticed that "https://googleads.g.doubleclick.net/" tabs only pop up when i click on widgets on my dashboard.

the more i click on widgets, the more tabs open up. this is super annoying and haven't found answers to this around the web yet.

i've tried blocking https://googleads.g.doubleclick.net/ through "/private/etc/hosts" but still no help.

any help / reasons why these tabs would pop up would be very helpful

I have the same problem since Mac OS X Lion. I use a widget that I have created with Safari from this site: http://wiealtistmeinbaby.info/. When this widget is loaded, a new tab with doubleclick will be opened. Maybe there also a problem with the adblock-extension. When disabling adblock the problem doesn't occurs but when enabling the extension in Safari the doubleclick-tab doesn't open too. My default browser is firefox.

I have solved this issue on my iMac computer running OS X 10.5.8 by running a scan with Sophos Anti-Virus for Mac Home Edition. The software found 21 threats and cleaned up 19 of them. I followed instructions from Sophos to remove 3 threats manually. After the clean up I no longer have Firefox launching the doubleclick ad tabs in my browser.

You can download and use the Sophos software for free from here:

http://www.sophos.com/en-us/products/free-tools/sophos-antivirus-for-mac-home-edition.aspx

I apologize to anyone who tried the above solution. It was a very temporary fix. The problem recurred very shortly after I ran the virus scan. But not immediately. This time I think I have it licked.

Reset your dashboard on Mac OS Leopard by following the instructions here: http://www.poweraxess.com/macintosh/osx/reset-dashboard-osx-leopard

Not sure if it is the same on Mac OS Lion, but it probably is. Remember to restart your system after you remove the two plist files.

Warning this will unistall all but the default dashboard widgets, but it will solve the problem with doubleclick.net ads opening in your default browser.

Warning this will unistall all but the default dashboard widgets, but it will solve the problem with doubleclick.net ads opening in your default browser.

But I like active info from web sites on my dashboard. Does this mean I get the doubleclick tabs whenever I make active dashboard items?

@bahiaballena I'm not sure if reinstalling widgets that get active info from websites will cause the problem to resurface. I'm not sure exactly what was causing the problem, where it was installed or how it got into the dashboard settings.

I have reinstalled widgets that are pulling active info and so far so good. I'm hoping that having Sophos anti-virus running in the background will help stop it from happening again, but who knows.

Baffling and annoying. I think that someone with a better understanding of the Dashboard than I would need to try and figure it out.

I had the same problem . Today I did a system update and now its fixed.