I've been trying to fix this problem for days now.
Like many others, my connection drops although the wireless signal icon remains full. The MBP thinks it's still connected but will not load any web pages. I have to turn airport on and off to rectify this (until it happens again after about 10 minutes or so of inactivity).
I recently upgraded to 10.7.4, hoping that would fix this issue. NOPE. When I was returning Tiger I tried a fix that I found on these forums which involved replacing a .kext file. This didn't work for me.
I only recently phoned apple support. They told me to remove the HD:Library/Preferences/SystemPreferences folder, which effectively reset my network settings. I thought this had fixed the issue, but later that day it happened again.
If you are having this problem my advice would be don't bother wasting your money phoning apple support. You'll just have to wait and keep your fingers crossed for a solution.
If anybody knows of a real solution to this problem, please let me know! __________I AM RELLY DESPERATE...
Edited by Dakeyras, 12 July 2012 - 01:29 PM.
Removed both Email addy' & phone num's for safety reasons.