Agreed, I had a similar situation. ipoint works, but you must have a complete uninstall of Logitech.
I would recommend removal utilizing Revo unistaller (be sure to create a restore point), and carefully go through the registries, before you make the final click of registry removal.
I have a mixed MS Keyboard and the VX Revolution, and I had to shiff around a bit, but I finally got all my buttons programmed with iPoint.