Catpart Icon axis is gray

[Tommer2]

Does anyone know what it means when the axis in the Catpart icon in the tree is gray instead of red? I've tried replacing, but get the error "there are no external links". This has happened several times over after inserting a new part to remedy the problem.
Also, I can still open the Catpart in a new window from it's current location in the tree.

 

[Azrael]

Doesn't that mean it is unloaded? can you right click and try to load it