Excessive Airport Scanning after 10.5.2

I've had this problem for the last FIVE months and I believe I may have finally found a solution. I have tried ALL the "fixes" in this and many other threads. My answer is to go to an earlier version of the Airport Extreme firmware. Somewhere along the several updates since I got my iMac, the dropping signals began. I kept wishing I could get things back to the first four months of flawless and speedy > 12 Mbps Download. This is what I did to get "back there"
1. Launch Airport Utility
2. From Airport Utility pull down menu, hold option key and select Check for Updates
3. Select earlier version [I picked Version 7.2]
4. Download
5. From Base Station pull down menu select your base station
6. Choose Manual Setup
7. From Base Station menu choose Upload Firmware
8. Select earlier version [7.2 worked for me]
9. Click OK

I'm having the exact same issues with my Macbook Pro 10.5.6. I am soooo frustrated!

I just upgraded to Leopard from Tiger, updated to 10.5.6 and had this issue. Also couldn't get MobileMe to sync.

SOLTUTION....

Don't show the Airport in the Status Bar (Preferences>Network>uncheck the box)

Airport no longer scans
Internet faster (of course)
MobileMe sync'd perfectly

Not sure if this works for everyone here, but it worked for me.

Hope this helps at least 1 person!

This is DIRECT from Apple support. They are the three things to do to fix this problem, in order of most likely solutions. I only need the first one to FOREVER solve this problem of scanning. BTW airport scanning occurs because the wireless signal has become too weak or has been dropped, so scanning for a better network signal will go on until you fix the signal problem itself.

*Apple Support Fixes for Airport*
1. UNPLUG [do not use reset button] Cable Modem. Leave unplugged for two minutes
2. Unplug Ethernet coming into airport from cable modem
3. Replug cable modem
4. Replug Ethernet
5. Restart MAC

*Reset hardware on iMac*
Hold down OPTION COMMAND P and R while turning on IMAc. Continue to hold until third chime or when you reach the desktop after the second chime then release all keys.

*Run Hardware Check*
1. Insert Disk 1 of OS install disks
2. Turn off Mac
3. Turn on holding down D key
4. Run limited or extensive hardward checks

I think I might have stumbled onto something if you remove the Airport icon from the top menu bar my network connection seems to not hang. This is probably because when you click the airport icon it shows you a list of all the available network connections and the monkey that designed that feature thought it would be a good idea to constantly scan in order to show you an updated list. I also set my networking configuration static but that did not stop the scanning or the seemingly dropped connections. I tried configuring my wireless router from AT&T manually but that did not fix the problem either. For the moment it seems that disabling the icon in the menu bar fixes the issue. Which would make sense if it was always trying to show you a list of all wireless networks.
Hope this helps.