My internet shuts off randomly

I'm not sure if this should go in the airport & wireless or the internet section, but here goes.

When i'm at home my internet shuts off randomly and i can't use msn or a web browser, although i'm still connected to the server.
the only way for me to turn the internet back on is to restart the computer, i did a diagnostic when internet wasn't working and it didn't help.

Also when i'm not at home this problem doesn't seem to occur.

And lastly! the problem began after the last update where you have to turn off the computer and hold the power button until you hear the tone.

Any ideas on what i could do to fix this problem?

Have you tried setting up another Users account on your Mac or running any maintenance scripts?

for the other user the problem still occurs, i'll try setting up a brandnew user to see how the **** flings it's **** (**** flies).

and i'm not exactly sure what maintenance scripts are.

I tried a new user account and the same problem occured!

do you know if restarting you computer a lot causes any long term problems?

Unless you've been restarting your Mac every five minutes or so for the past five years restarting every now and then shouldn't cause problems. Here's some info on maintenance scripts-
http://www.thexlab.com/faqs/maintscripts.html