For some reason wireless does not automatically not switch itself back on after being out of network coverage, say on the tube, i have to go back in and switch it on manually

I've had theat problem w/ a few different phones. Could be the strength of the signal in your area. My house has horrible service (TMO, VZW, Cingy, etc) and sometimes I have to turn it off then back on again. It happened w/ my old Nokia, too.