When you resume a Windows XP SP1 computer from standby, the wireless connection icon in the notification area shows as unavailable?
This problem is occurs because the media connect action is NOT properly sent to the Wireless service.
To work around this problem:
1. Control Panel / \[Network and Internet Connections\] / Network Connections.
2. Right-click Wireless Network Connection and press Disable.
3. Right-click Wireless Network Connection and press Enable.