WiFi Limited Access, Signal Strength Excellent, works if I reconnect

Alienware X-51
Win 7 Home Premium SP1
Thompson TG585 v8 Modem /WPA2-PSK

Scope of Problem:
This is a Desktop LOADING based problem.
NOT a connection dropping, fading while in use problem.
Other Devices work fine.
Same problem with previous Modem.

Problem:
Login.
Wireless icon shows spinning busy symbol.
If it connects fine, then it will Remain fine until the next Restart

If connect fails then yellow exclamation mark shows over TaskBar Icon.
Viewing connection it shows as Limited Access, but signal strength is 5 Bars
A Manual Disconnect, then reConnect will always establish a working connection (sometimes needs two attempts).

Signal Strength is ALWAYS Excellent, No other devices have issues with WiFi.

This is a persistent and long term problem which has "survived" improved Modem placement , ISP directed settings changes, and a new Modem.

[ Other threads all seem to be about No Connection OR Dropping/Fading/Poor Connection. This isn't ].

Modem was the problem.

Recently the Thomson V8 was replaced with a telco provided Huawei HG630B.
The issue disappeared instantly, there is now just a little lag and then connection.

So problem solved.