ANOTHER Airport Extreme base station dropping connections

Question

I think my network connectivity problems predate the latest Airport software update by a few days.
Our MacBook Pro's randomly drop an Airport connection when they are near a secondary access point operated in Bridged Mode.
My one-year-old Airport Extreme/Time Capsule had been working fine in 2.4GHz b/g/n mode with a gigabit switch and a link to a Comcast cable modem, all set up in the northwest corner of the house. I decided to replace it with a new, dual-band Airport Extreme/Time Capsule so that we could separately operate a faster 5GHz "n" network for modern notebooks along with the 2.4GHZ b/g/n network for older notebooks and iPhones.
We substituted the new Airport Extreme/Time Capsule for the old model and it now serves IP addresses to 5GHZ network devices. The old Time Capsule was moved to a new location in the southeast corner of the house, connected to the network via Cat 6 Ethernet, and also set it up to join the same 5GHz wireless "n" network in Bridge Mode -- it is an access point, but not serving DHCP addresses.
Now, whenever a laptop is near that device, it accesses the LAN through that Airport Extreme's 5GHz WIFi connection. The problem is this: every few hours (though sometimes sooner - its random), our MacBook Pro's lose their network and Internet connections (not simultaneously though). This only happens if the laptops are physically closest to the older, Bridged wireless access point. It can happen in the middle of Web surfing and always, when they wake from sleep. It NEVER happens if the notebooks are physically closer to the new Airport Extreme (and hitting it's 5GHz signal) and the iPhones NEVER lose their Internet connection to the separate 2.4GHz b/g/n network.
When it does happen, we have to Restart the notebooks to re-establish an Internet connection, though I suppose restarting the Airport Extreme/Time Capsule also might re-establish the connection. Sometimes, I can just move my laptop back to the northwest corner where the main Airport Extreme/Time Capsule is located and get right back online through that access point. But usually, I just sit in the back room, restart and rejoin the network through the secondary, wireless access point. Turning off/on Airport (at the MacBooks) accomplishes nothing and neither does Network Diagnostics.
This affects two new, MacBook Pro "n" laptops running 10.5.8, but does not affect the iPhones. So, it only seems to be a 5GHz issue. I don't think it's RF interference because I've tried three different 5 GHz channels. I've also tried reducing the secondary Airport Extreme's transmission power to 50% and, more recently 25%, to no avail.
This morning, it started happening again, so I finally used the Airport Utility to turn off the Wireless Mode of the secondary device for my next test (thanks to the Ethernet connections, it's still visible on the wireless network). We'll see if this solves the wireless connectivity problem.
Does anyone have any idea what could be causing this? I wonder if it is some odd, configuration issue.

Answer 1

I just started having a similar problem in the last week. I have three devices: the Gigabit AEBS is connected to my cable modem and is the DHCP server. An Airport Express (N) extends the wireless network. A second (G-Only) Airport Express is connected to one of the gigabit ports on the AEBS and creates a second wireless network for iPhone, G-devices and guests.
Lately, the connection from my May 2009 MacBook Pro has started acting strange. The Airport icon in the menubar shows I have full signal strength, but I'm no longer connected to the Internet and I can't browse other N computers on the network. Devices that are connected via the G network continue working fine and remain connected to the Internet. This is interesting because even the G network has to go through the AEBS to get to the Internet. It only appears to affect the Internet connection via the AEBS's own WiFi but not its ethernet ports. If I open Airport Utility from the MacBook Pro, the AEBS status shows as Normal. Turning off/on the Airport on the MacBook accomplishes nothing but I can restart the AEBS from the Airport Utility and then everything goes back to normal. A few hours or more later, the problem occurs again.
By holding the Option key when clicking on the Airport icon and looking at the Airport MAC address I can tell that the MacBook Pro is connected to the WiFi-N via the Airport Express extender. Like you, I may have to try and shut that one off and see if the problems occurs when it is connected directly to the AEBS. The problem with that is that since it is farther away in the house, the signal strength and thus my transmit rate will be slower. I'd be curious to see if your experiment by shutting down your secondary AE will still cause drops.