The subject behavior is probably the result of your wireless adapter not being fully compatible with the Windows XP Wireless Zero Configuration service, which is enabled by default.
To fix this problem:
1. Control Panel / Administrative Tools / Services.
2. Double-click the Wireless Zero Configuration service.
3. Select the General tab.
4. Press Stop.
5. Configure Startup type as Disabled.
6. Press Apply and OK.
7. Obtain the latest driver for you wireless adapter by visiting the manufacturers Web site.