What exactly do you mean by "can't get to the IP address"? You can't ping it, use the web interface, can't use the programming tool? Is the system still functional? Little more detail will help, but if it still responds to a ping but nothing else it might be a bad/flakey sd card/slot. I've seen some bad ones on the 7000 series switches, that sometimes just a few rapid reseats of the SD card solves the problem.