FRUSTRATING!! 4 month 27" iMac. WIFI drops every few mins.

Question

I have a 4 month 27" Intel iMac. The WiFi connection drop every few minutes.
I called up phone support and they told me to move the router away from magnetic fields so now I have 'stuck' it to the ceiling of my apartment away from the Cordless Phone, TV etc....
Power Cycled the Modem
Updated the Mac Software
Called up the cable company to check for Firmware updates
Updated firmware on the wifi router
I then too the iMac physically to GENIUS - they kept it for a day and ran checks but did not find any issue with the system
Renewed the DHCP Lease as advised by someone on this forum
All possible approaches
Point is - this does not solve my problem. I have to click disconnect and re-connect WiFi every few minutes. It 'drops' while drafting a mail and then you have to reconnect to SEND the mail OR when streaming a movie 'LOADING' every few minutes and you have to re-connect.
What is the point of a high end computer when it cannot hold on to a wifi which my $500 Dell holds seamlessly and so does my iPhone and Wii.
Anyone have a concrete solution?

Answer 1

Hi
I may have a fix for you.  It requires you to change your WiFI security from WPA/WPA2 to the (lower) security but effectively still pretty secure WEP.  You can use the 128bit security.  Some routers seem to have a problem with the passwords of WPA - I don't know the technical stuff but its happened to me not just on a mac network but on a Windows XP network aswell.  I offer this to you because it worked for me, and is still working.
The thing to do is to log onto your router and change its security from WPA to WEP.  To do this open your browser of choice and type in the ip address of your router.  eg. 192.168.1.2  The side of your router should have this address displayed.  If you have changed your router's ip address for some reason you need to use that address, obviously.
Navigate to your security page on your router.  You may have to type in an Administrator password for the router.  (this prevents anyone with a bit of knowledge randomly, or maliciously changing your settings and locking you out).
Select WEP security, and select 128bit if you have the option.  This will give you a passkey of 26" bits" long.
Type in your new security password.  Write it down EXACTLY as you type it.  Remember, for WEP you can only use Hexadecimal - so numbers 0 to 9 and letters a to f in any combination.  JUST make a note of it exactly, as if you don't, getting back on your router via wifi will be impossible.
Next on your iMac, or whatever, delete your wifi network connections.  You could also delete your wifi connection in Network Preferences,  and start again.  To make things absoutley sure you can edit your keychain and delete the keychainentry for your old WPA wifi network name aswell.
Now, in Network Preferences under Network Name type the SSID of your wifi network exactly as it is on the router.  The iMac will find the network and offer you a box to enter your WEP password.  Type it in exactly as you remebered/wrote it down.  You should now be connected to your Network using WEP security. 
You shouldn't have any more problems with dropping wifi connections after sleeping your iMac and in most real world situations you will still be spretty secure.
I offer this fix "as is" - if you don't feel competent to make the changes then don't - just ask someone who does know!
David