XPS 420 Vista audio stutter (wireless driver upgrade solution?)

From some of the other threads here it appears that the audio stutter I get in Vista in iTunes and Windows Media Player is due to some interaction with my Netgear WG311T card in Vista. One suggestion has been to get a new driver. 

The most recent drivers from Netgeat appear at
http://kbserver.netgear.com/release_notes/D103110.asp
and were published May 22, 2007.  Those are the ones I am using. The driver in this package appears to be 7.2.0.16401.  When I do a search from the update driver menu from Control Panel it says it is up to date.

Following  another suggestion I went to to http://catalog.update.microsoft.com/v7/site/Search.aspx?q=WG311T to find a newer driver. I saw that there are two Atheros 7.4.2.75 drivers there dated 5/7/2008. When you download them you get two cabinet files. One of them starts AMD64 and continues with loads of characters and the other starts X86.

The AMD cabinet file contains
athrextx 32.7 KB, athrx.sys 937 KB, and netathrx 104 KB

The X86 cabinet files contains
athr.sys 749 KB, athrext 32.6 KB, and netathr 104 KB

I pulled the athrx.sys and athr.sys files out of the cabinets and into a directory. I then went from control panel to the driver page for the netgear and the update driver option. I had it look in the directory where these two files were and it came back with "The Best driver for your software is already installed"

So, has anyone done something similar to this to solve the audio stutter problem and how can you get Windows to accept a new driver when it thinks you don't need it?   Which of the drivers listed above is right for use with the XPS 420?

Thanks,

Neil