What is this little arrow on top of a tab in Google Chrome?

From time to time, but very rarely, I get a little arrow on top of a tab in Google Chrome as you can see in this picture:

What is this little arrow on top of a tab in Google Chrome?

Why is there? what does it mean?


Its the drop location marker when drag/dropping tabs, and it's been left behind due to a repainting bug in google chrome, as outlined here:

http://www.google.com/support/forum/p/Chrome/thread?tid=431479d60ebaa2d1&hl=en

Changing theme should fix it.