I have had an iMac for around 3 weeks. When i first used it the wireless was perfect with full signal. I went out last night and my mac was left on but in power save. I woke it up and now for some reason i can't hardly get a signal from my wirless, all i can get is 1 bar. Why has this done this considering it has been running perfect since i have had it. I have not changed my router, mac settings or anything else. I also have a PC Laptop in the same room and this gets full signal all the time. Hope someone can help.