I just read the the footer and mine wasn't software it was damage after my husband changed the screen. I could reset it and like you say when you tried to alternate the cameras they froze. I tried all the restores through iTunes and got no where. I was assured by iPhone repairs direct that it was a hardware problem caused by damage when taking the phone apart and although I was sceptical they did fix it - permanently :)
I just looked up the number and its 01924 262112 - don't think they will mind me writing it here - they were very helpful