Toshiba laptop with Atheros AR5008X won't connect to Linksys WRT350N

Question

Please excuse the level of detail, but I believe you need a reasonably complete picture if you are to understand the problem well enough to give a complete answer.
SETUP & BACKGROUND
I have three N-compliant devices and several G-compliant devices on my network. I also have two routers, one being used an an access point. The first is a Linksys WRT350N; the second is a Linksys WRT54G. I have the G router connected as an access point so that I can reserve the N router for the N devices and achieve N speeds.
N devices:
Toshiba laptop; network adapter is Intel 4965AGN.
Toshiba laptop; network adapter is Atheros AR5008X
Lexmark Wireless printer
Router settings:
WRT350N: Security Mode WPA2 Personal; Encryption AES; Network Mode N-only; Radio Band 40MHz.
WRT54G: Security Mode WPA Personal; Encryption AES; Network Mode Mixed
The best I can recall, I set the WRT54G to WPA Personal instead of WPA2 Personal because one of the G-compliant devices did not list the WPA2 Personal setting -- but this is based on memory only.
To reserve the WRT350N for the N devices and achieve N speeds, I set the Wireless Mode to N-only and Radio Band to 40MHz., and each router broadcasts its own unique SSID. Once I set everything up, I saw a substantial increase in the link speed reported by the Toshiba Connectivity Doctor (I realize there are issues about taking these numbers at face value, but let me continue). The Toshiba Connectivity Doctor reported WRT350N link speed at 130 Mbps and everything appeared to be working well.
PROBLEM
Until recently, no problems were apparent; the Toshiba Connectivity Doctor indicated the two laptops connected to the WRT350N at 130 Mbps, the printer connected to and printed via the WRT350N, and all G devices connected through the WRT54G. Recently, however, network performance declined and the Toshiba Connectivity Doctor indicated erratic link speeds ranging from 1 Mbps to 130 Mbps.
I found through a little research that my quest to reserve the WRT350N router for N devices lacked one element: according to Linksys help for the router, setting the N Transmission Rate to anything other than Auto results in denying access to B/G clients.
I set the N Transmission Rate to 270 Mbps (the highest setting). The Linksys printer works fine and the Toshiba Connectivity Doctor indicates a solid 130 Mbps link speed for the Toshiba laptop with the Intel 4965AGN adapter card.
The other Toshiba (with the Atheros AR5008X adapter card), however, is now only able to connect to the WRT54G (the Toshiba Connectivity Doctor indicates a solid link speed of 54 Mbps to the G SSID). If I reset the WRT350N N Transmission Rate to Auto, the Toshiba with the Atheros card can once again connect to the N Router -- but the erratic link speeds and the network degradation returns also.
I have verified that the Atheros AR5008X network adapter is N-compliant. There aren't many settings on the Atheros AR5008X adapter card configuration, but I can find no documentation on the Internet for this card.
As far as I can determine, all firmware is up to date for both routers and all drivers are up to date for both adapter cards.
I'd love to know what changed in the first place, but I'm more concerned with fixing this problem. Anyone have any ideas as to how I can get the Atheros adapter card to connect to the WRT350N with the N Transmission Rate set to something other than Auto?

Answer 1

Atheros adapters using windows drivers wont work with N routers, ive read somewhere
Download drivers at: http://www.atheros.cz.
Updating wless adapter sometimes can affect your pc sound quality for some reason.
Best call atheros for your concern
or call Toshiba: TOSHIBA: 800-316-0920
Example of adapters with windows driver that wont work with N routers:
Atheros AR5008 Wireless Network Diver 8.0.0.279 Windows 7(32/64-bit)
Atheros AR5008 Wireless Network Diver 9.0.0.173 Windows 7(32/64-bit)
Atheros AR5008X Wireless Network Diver 7.7.0.429 Windows 2000/XP(32/64-bit)
Atheros AR5008X Wireless Network Diver 7.7.0.449 Windows Vista(32/64-bit)
Atheros AR5008X Wireless Network Diver 7.7.0.456 Windows 2000/XP(32/64-bit)
Atheros AR5008X Wireless Network Diver 7.7.0.481 Windows 2000/XP(32/64-bit)
Atheros AR5008X Wireless Network Diver 7.7.0.523 Windows 2000/XP(32/64-bit)
Atheros AR5008X Wireless Network Diver 8.0.0.279 Windows 7(32/64-bit)
Atheros AR5008X Wireless Network Diver 9.0.0.173 Windows 7(32/64-bit)
Atheros AR5xxx Series Wireless Network Driver 5.0.0.107 Windows 2000/XP
Atheros AR5xxx Series Wireless Network Driver 5.1.1.9 Windows 98SE/Me/2000/XP
Atheros AR5xxx Series Wireless Network Driver 5.3.0.35 Windows 2000/XP
Atheros AR5xxx Series Wireless Network Driver 6.0.2.75 Windows 98SE/ME/2000/XP
Atheros AR5xxx Series Wireless Network Driver 6.0.3.100 Windows 2000/XP