This problem occurs due to various timing issues involving authentication and the resume process. The authentication process is starting before the hardware is ready or before the initial wireless connection is established.
Even if you are not using WPA2 in your network, the following optional update for XP SP2 is known to help concerning this problem in any WPA or 802.1X mode (including RADIUS):
The Wi-Fi Protected Access 2 (WPA2)/Wireless Provisioning Services Information Element (WPS IE) update for Windows XP with Service Pack 2 is available
If you do not have Administrator rights to your computer, the best course of action would be to ask your an Administrator to apply this update for you.
Otherwise, you may also mitigate this problem by either logging out or turning off your wireless card before suspending. Many newer laptops are equipped with a switch either as a Function Key (Fn) or an actual switch somewhere along the outside casing with the symbol ((())).