Image with two same pool bars?

On post #913886, the Pixiv 1000 bar is there twice. Anybody got a clue on why this is happening?
http://img546.imageshack.us/img546/3036/twicepool.png

It also happens on post #913904.

This happens in both Firefox and Chrome, so I don't think it's a browser thing.

It's showing up like that for me too, I don't know why.

Removed and readded to the pool to fix it. This happens pretty regularly, actually.

If you repeatedly click on the "Add to pool"->Add-Button, the image is added multiple times.