Item Count marked as 0 when right-clicking on an armor stand with a custom skull

In the image, the skull in my hotbar has a count of zero and is colored red, instead of being white and having a number one or greater.

There are not a bug, It is displayed in red because it is not possible. Same for the negative value (http://puu.sh/aQTpD/2750a7476e.jpg)

Unable to reproduce.

Ok, thanks!