That is always worth a shot before giving up.

When you connect to the WiFi network, in the status bar is there a question mark overlaid on top of the globe (to the left of the battery status icon) or is there a steady (and not flashing) antenna overlaid on the globe?

If you see a question mark it means your device is not being assigned an IP address.

If you see an antenna, go into Tools -> Connection Manager and within the Connection Manager application open the application menu (press the Menu button or click in the application title bar area) and in the Internet connection menu item click on "IP address". Check that your ip address and other details are correct - if you're not sure, copy all of the details into this thread and it may shed some light on your problem (it would also help to know what subnet you are connecting to at the time you review the IP address information).