The device cannot be reset if there are active connections pending. Close all the applications which have connections active, e.g. the following:
- Web browser
- Email applications
- Set home screen to offline mode (Options > Content to offline mode)
You can also try to force the connections to be disconnected by selecting the offline profile (Menu > Settings > Profiles > Offline > Activate). Note that even though the device is switched to offline profile, there may be WLAN connections still active.
To see if there's a connection still active, select Menu > Settings > Connectivty > Connection mgr. The pending connection can be closed by selecting Options > Disconnect.