Durring checkout if a user edits their address they will see "state: undefined*" even if the user has selected a state previously. Then when they press "ok" they will be redirected to a 404 error page. this is a video of the process to get the error.
ipcfix.com/help/ipc_edit.mp4
The site is ipcfix.com/store
I am using joomla 2.5.2, hikashop com_hikashop_business_1.5.6_2012-02-22
I had this problem with joomla 1.7.4 and a previous version of hikashoop, I just upgraded to see if it would fix the problem, it did not.