My iPad lost connections to the Internet although all signs indicated that it’s connected to my network. I found many others are experiencing this wireless connection problem also. Apple has issued instructions on this issue. They suggest the following:

• Create separate Wi-Fi network names to identify each band. This can be done easily by appending one or more characters to the current network name.
• Example: Add a G to the 802.11b/g network name and an N to the 802.11n network name.
• Ensure that both networks use the same security type (WEP, WPA, WPA2, and so on)
• If the issue persists, reset your network settings using Settings > General > Reset > Reset Network Settings.