You need to check the setting in activesync to allow net traffic pass through.
From the help file:
Use ActiveSync to "pass through" this computer. That means the connected device can use the computer's network connection as if it were its own. You can use this feature to perform tasks such as downloading non-Outlook e-mail messages, to connect directly with Exchange Server, or to browse the Internet.
Important Note For additional security, disable network bridging on the PC (specifically, bridging to a Remote NDIS adapter) before connecting to the PC to pass though to the Internet or a network. For more information on network bridging, see Windows Help on the PC.
- Click Connection Settings.
- Select Open ActiveSync when my device connects.
- In the This computer is connected to list, select a connection to which this computer should connected when passing through ActiveSync.