I have been working on this problem for a while (a year or two) and have yet to find a solution anywhere
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While I am connected to the internet I hit random drops in connection. My airport bars are full but I can't connect to the internet. (I have done TONS of solutions such as reset my preferred networks, repair/replace keychains, move my router, and many more etc)
I also run into self assigned ip address errors whenever I set my network settings to automatic DHCP. It is extremely annoying, because I do not want to set my laptop settings to static, because of its incompatibility if I join other routers.
The only solution I know for both of these problems is: for the random drops to cut off my airport and turn it back on and for the self assigned errors to set my settings to static. Both of these solutions are very tedious and annoying when trying to connect to the internet for a long period of time.
It would be awesome for a real solution to both these problems! I hope someone out there knows whats wrong. Thanks!!!!
Ps. I am running Leopard (which may have its problems too) but that shouldnt mean its not compatible!