I am running an approx 2 year old Macbook on my wifi network and have noticed that the download speeds are very slow all of a sudden. Testing with speedtest.net I am only getting 0.5MB/s compared to normal speeds of 2.5MB/s. I don't think it's the router because my iPhone is consistently showing 2-2.5MB/s. Any ideas? I have run software update to ensure everything is up to date. The only changes that have happened in the recent past are switching from WEP to WPA2 security on the router and making the wifi network invisible. These haven't affected the iPhone as noted above.