Strange Airport Issue. Is it software or hardware?
My MacBook Pro, A1261, has this strange AirPort issue. My AirPort will work fine on my mac and i can connect and browse the internet. Sometimes the computer will go through 30 power cycles and not have any glitches but then it will either freeze or drop the wifi. If it drops the wifi it starts to say wifi off and when i click turn wifi on it highlights but never turns on. If it freezes I have to do a hard reboot and it will come back on and say "no wifi hardware installed." It will also say this sometimes after i reboot it when it doesn't allow me to turn the wifi on. After a second restart everything goes back to normal and it works. It when I received the computer the wifi would only work with the top case off and would give me the no hardware message when the top case was on. I then removed the wifi grounding clip and it doesn't do this anymore. I have reinstalled snow leopard and put loin on it and it still has issues. Do you think it is the Airport card of the i/o board?
Have you applied all of the OS updates? Are you running any add-ons in the OS or any odd browser extensions? Upgrading the OS alone doesn't prove or disprove software or hardware.
I'd start making sure the system was clean Virus or Malware and then check the hard disk - errors and fragmentation. Use Disk Utility booting from an external HD or the OS-X Install DVD, any defrag utility will do. Make sure you have a back up just in case when using either.
The fact you had issues with the case and grounding clip tells me you have a bad connection with the WiFi card but it doesn't explain the system hanging. The only thing I can think of is an exposed power line that is shorting to ground. Make sure you don't have a pinched ribbon or wire.
It you did I would have thought it would effect you every time you ran your system. Are you twisting the system in some way that is causing it to short.