I have a strange problem that neither phone calls to Mac Technical Support or to the authoried dealer that sold me the computer have been able to solve. I bought a 17" MacBook Pro, now running OS 10.6.2, a couple of weeks ago. Every once in a while, the computer simply goes off line. The Network settings in System Preferences are all correct, and I know that the problem is not with my cable connection since my wife has an older MacBook Pro running on the same Airport hub and using the same network Her internet connection remains open when mine shuts down. Curiously, I can get back on line with a simple Restart. Can anyone suggest an explanation of why this is happening?