How broken is z-index implementation on Chrome?!

Almost an hour lost today, due to perfectly fine web code running on Firefox, but showing completely wrong z-order on Chrome.

The reason? I manually changed the z-index of a child and not the one from the parent DIV. (and I was only making the child z-order *higher* than everything else on screen, so I could drag it around)

Code now has a bunch of "// thanks Chrome!" to show due appreciation. Grrr....