In the past month my 1 year old MacBook has become real flaky when surfing the Internet. Sometimes webpages open quickly, other times I get stalled while "Connecting to [the site]...", which usually leads to a network error screen. It's not Safari because I get the same behavior from Firefox. I changed the DNS settings to open DNS servers, but that didn't help. The problem only seems to be when I connect wirelessly; it's flaky on both my home (airport express) and work (time capsule) wireless networks, but fine if I plug in via cable. I did an experiment at home using my iMac and MacBook: After confirming that the network settings for each were identical (except for their IP addresses, of course), I tried to open the same webpage in each one simultaneously. The iMac opened it in about a second, the MacBook stalled and eventually gave the error page. Screen sharing and transferring files between them works, though it seems like file transfers might be slow (20 mins for 100 MB, is that slow?). I took it to the 'genius' bar and the guy there told me to wipe the HD and reinstall Leopard and see if that fixes it. Should I take that advice (!), or does anyone here have an idea of what else I could try first?