Mixture of Wifi Questions (Extend network, Wireless Radio, etc)

Question

Hey Apple Forums!
So here's the main issue. I've set up a network consisting of two routers. The first is a TC Dual-Band 2 (firmware 7.5.1) and the second is a TC (firmware 7.4.2). The first is connected to the internet and the second is in bridged mode; rather than being used in a WDS, I've set the second to extend the network of the first one, and I've made sure that the first has "Allow this network to be extended" checked. Neither one have any ethernet clients, just wireless. We're using DHCP, a WPA/WPA2 password, and the radio frequencies are automatic (2.4GHz N(B/G compatible), 5 GHz N(A compatible)).
As for the clients, we have a Wii, Xbox 360 (A/B/G wireless adapter), two macbooks (both 4,1), an iMac ('09-'10)), an iBook ('03-'04), a G4 Cube, and a Powerbook (12' Alum). Right now I'm operating all Network Administration from a Macbook.
I set up the second router to extend the first because we have the Xbox 360 and Wii in a room with poor signal, and we often traffic in there with the macbooks. Being the tech junkie and certified network technician, I thought back to my schooling and remembered that the more users on the network, the more the signal degrades over distance; this meant that we needed something to cover the room or else nobody would be able to connect in there (and if they could, the speed to do so would mimic dial-up. Yuck!). So I had it extend the first, have the WPA/2 key change every 12 hours (the homes here are spaced out, and if someone wanted free wi-fi they could use our Guest network)
I'm see two things wrong. The first is a random drop in our connection to the internet. While it may not necessarily be the router dropping it as it could be the network being too busy, we experience a 5-15 second block to connect to the internet perhaps around the hour and at random times. We did not have the problem before I set up the second router to extend our Dual-Band. However, I looked at the logs on the second router and found that the TKIP key was being rotated every few seconds
Aug 15 10:01:06 Severity:5 Rotated TKIP group key.
Aug 15 10:01:13 Severity:5 Associated with station 00:21:47:b5:20:d7
Aug 15 10:01:13 Severity:5 Installed unicast TKIP key for supplicant 00:21:47:b5:20:d7
Aug 15 10:01:23 Severity:5 Disassociated with station 00:21:47:b5:20:d7
Aug 15 10:01:24 Severity:5 Rotated TKIP group key.
(repeat every 1-4 minutes)
because our Wii was attempting to connect. I saw that I had set it up to connect with a WPA/WPA2 (AES) key, and promptly switched it to a WPA (TKIP); I cannot confirm the changes yet, but I figured that this may help slightly. I noticed no errors reported on the first router via logs, but did notice
Aug 15 09:30:03 Severity:5 Connection accepted from [fe80::21e:c2ff:feaf:8c1e%bridge0]:52084.
being spammed every few seconds or minutes. I figure this is normal and part of the bridge
Now the second isn't really a problem as I see it to be...wasteful. I know that the Dual-Band 2 uses the 2.4GHz as the guest band and the 5GHz for the secured wireless by default. When you put it into "allow to be extended", I found that both signals were broadcasted in BOTH frequencies. I used iStumbler when trying to determine the optimal placing of the second router, and found a duplicate network for our secured and guest networks. I'm guessing this is supposed to happen to allow routers with other frequencies to extend the signals (like how our second router is 2.4GHz only but can extend the 5GHz secured network), but to me it seems as though the router would be wasting power and time if the signals are being rebroadcasted (1 packet in 2.4GHz, 1 packet in 5GHz; wasting a few milliseconds that build over time) when they could stick to a single frequency. So the question is, can I swap the guest and main network frequencies to stop this redundant broadcasting as well as allow my secured network to be only in 2.4GHz mode?
Any questions, answers, or mere statements of information is appreciated!

Answer 1

Ok, so the TKIP key rotation and disassociation may be normal due to the encryption standards for both it and CCMP. However from what little I've found, the original Time Capsule using firmware 7.4.2 may be causing the intermittent drops
http://discussions.info.apple.com/thread.jspa?threadID=2037306
I'll try this tomorrow and see using my Xbox and Macbook (UDP streaming and TCP to be covered)