Extending WiFi using AirPort Extreme and AirPort Express
I am extending my AirPort Extreme network using an AirPort Express. Everything is set up according to the instructions here: http://support.apple.com/kb/HT4259?viewlocale=en_US&locale=en_US All lights are green and my network is extended.
The problem is my iMac seems to revert back to connecting to the AirPort Extreme even though it's close to the Express and gets a much better signal from the Express. AirPort Utility shows that my MacBook Pro is connected to the Express and speedtest.net shows its on a MUCH faster connection than the iMac. I have my MacBook Pro sitting next to the iMac now.
Can I force the iMac to connect to the Express? If so, how?
Running the latest Lion on both machines, iPad and iPhones seem to connect to either base station just fine.
iMac (21.5-inch Late 2009), Mac OS X (10.7.3)