Vista Wireless Problems: Connected with Limited Access / Local Onlyetc

Hi,

I'm having problems with one of my desktop machines which has Vista
Ultimate 32 bit installed. It has a Netgear WG311T network card. It is
having strange intermittent problems with the wireless connection.
There are 3 other wireless machines on the network but they are
running Windows XP and Windows 2003 Server. I have had the wireless
running on this machine using the same hardware and even the same
driver for over a year. But with this fresh clean install its giving
me problems.

The problem is very intermittent. Sometimes it will connect if I do
diagnose this connection or ipconfig /renew. Sometimes I get local
access only. Sometimes it doesn't connect at all and doesn't even find
the network.

I've tried all the suggestions on websites I've read including:

Disabling power saving on the NIC
Disabling IPv6
Disabling QoS
Changing wireless channels

Does anyone have any other suggestions because I'm really stuck.

Many thanks!