hello, I am a new user of mac. I had good browsing speed so far. but in these three days, I don't know what exactly happened to my mac. It takes more than 10 seconds to open ordinary pages like google/wiki. and I am sick of it. I thought it might be the modem, but actually not. cus my friend came with his laptop and the speed was pretty good in his. May be I was downloading some musics from a non secured site........... , but would that be a problem? the downloading speed is more than 20Mb/s from speedtest.net but is unbelievably very very slow. please, let me have ur help.