I've usually managed success with the "enable guard mode" option checked, and making sure the unit is fully reformed before charge.

However, this still doesn't help when a unit is "screened" by say, dispersed routing crossbowen or a few skirmishers. All the more frustrating because the charge should logically trample them over.

Not sure if 1.2 fixes this, as I haven't had the option to really try much.