My core i7's wifi has been acting up like crazy the past couple of days. I had the same wifi issue with my previous iMac alumn 2.4 and my macbook 2.4 Wifi speeds are so sporadic. One minute it's super fast. Another it slows to a crawl. When plugged directly into ethernet, it's always fast. I moved my router right next to the iMac so it's not a signal issue. But I prefer it to be in another room since I use slingbox with my cablebox. I've research this issue. This is a known Apple problem. Why hasn't Apple fully address the slow wifi issues. My Sony Vaio laptop and Gateway Laptop connects to my wireless network anywhere in the house without any issues. I've tried changing the channels (default is 6) to channel 11 or 1. This helps for a while than the internet slows down again. Same thing with changing the DNS. It's not my router. I tried the Netgear, Linksys and my old Belkin router. It's on WPA2. I'm a techie (had one of the original Linksys routers way back in 2000) so I know my routers. What's Apple's problem? Any other suggestions for me? I am very dumbfounded. Hey at least my iMac core i7's screen appears perfect and it's quiet the majority of the time...but wifi sucks at this point. I doubt it's a hardware problem either since it does work from time to time.