There are phantom triangles on top of the warning bubble when low-rep users downvote a post:
I'm running Chrome 40.0.2214.115 m on Windows 7 x64.
You have caught my attention on this one. A fix has been pushed and will build out soon. I also want you to know that our design team has been hard at work at converting all of our .less files to a consistent and uniform layout which will solve most of these issues in the future. Thanks for the report and we'll keep you posted on the status of the conversion.