Apparently we have a new messagebox:
Can it please be screen-centered or near the action I took?
It is on the top but I clicked to delete a comment on the bottom. The mouse movings give me muscle ache.
You have updated to the new chrome.
This is a regular confirm box, in the new chrome update (Version
29.0.1547.57 m on my machine) they have changed the look and position of the confirm.