Do you have any IP Address widget? if yes, it can help you to check if you have connected successfully and obtain IP Address.
If not, open X-Terminal
type below:
sudo gainroot
ifconfig
you will see many information come out, scroll up and check under "wlan0", you should see "inet addr", see if got any IP Address there.
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It'll be easier if you have IP Address widget.
If you're able to obtain IP Address, then most probably it's the DNS problem.
The easy way is to set the connection manually:
Create a new connection, at the end of the screen, there is an "Advance" button, which you can key in the DNS Settings.
If you're using normal Streamyx, key in the below DNS:
Primary DNS: 202.188.0.133
Secondary DNS: 202.188.1.5
OR, you can check this from your PC Window's Internet Connection status screen, go to "Support" tab then click on "Details" which will show you more information (or open command prompt, type "ipconfig /all").