OH - well you may want to go into your profile and see if you have this super annoying
setting turned on.
If you click your username top right to get to your profile, then look for "Edit Options" in the left hand menu, you will see a check box about halfway down that says this:
If you are browsing the forums when you receive a new private message, the system can pop-up a notification box informing you of the new message.
Show New Private Message Notification Pop-up
Make sure that you un-check that box and you won't see that pop up.
However, anything that took you to a cricut site is something different.