Right-click on portrait to open inventory also initiates movement

What the topic says.

When I right-click on a character portait to open the inventory (just like in IE), it opens the inventory, yey! However, it also commands the selected character to move to the spot under the portrait. Interestingly the character will move there even if that spot is already occupied by an NPC, as you can see in the attached image.

I expect right-clicking on a portrait only open the inventory and not affect the current selected character(s) at all.