I have the exact same problem with my razer naga hex mouse. It wont function until I unplug it and plug it in. updated mouse firmware (already had latest version), bios, chipset drivers, u name it. Issue happened on win 7 home premium 64bit, recently upgraded win8 64bit (with newer drivers) and exact same issue. Annoying.
I plug the mouse into a laptop and it powers on perfectly when the cpu boots. I wonder if there's a special bios setting, but I've fiddled with everything from legacy support to power management profiles. nothing changes it. I hope someone posts a solution, been researching for 2 weeks.