Encounter the same problem with Intel 2200BG. On another Compaq notebook using Broadcom wlan chipset, works perfectly fine. In my case, the problem started after I upgraded the firmware to the official Asus firmware 1.9.7.5 release.
This is what I get from Intel's website which sort of describe similar problem and the solution for the problem we're encountering :
- PSP (Power Save Polling) Causes Connection Issues With Some Access Points --> http://www.intel.com/support/wireles.../cs-006205.htm
- 802.11 Association Lost with Cisco* AP Configured for World-Mode Legacy
--> http://www.intel.com/support/wireles.../CS-022146.htm
- Stop Message When Running Older Intel Drivers after Upgrading Cisco* AP Firmware --> http://www.intel.com/support/wireles.../CS-022538.htm
The first suggestion I tried but problem persisted. Is there any way to disable "World-Mode Legacy" in the Asus WL-500gP??