I work for a large healthcare system that has a very large LWAPP deployment. We utilize the network for laptops, 7920 IP phones, and the new 7921 phones. We have HP laptops with Intel wireless cards. We have both the HP 6120 and 6320 laptops with the Intel 2915 and 3945 Intel wireless abg clients. There has always been a beacon interoperability problem between these intel clients and lwapp. This has been a huge issue that neither Intel nor Cisco has wanted to deal with.
The problem has finally been resolved with LWAPP code release 220.127.116.11. I upgraded my 4404-100 controllers to 18.104.22.168 to fix some possible arp issues I was seeing on our new Cisco 7921 phones. Not only did it resolve the arp problem, all my Intel problems went away.
It was interesting because I did the upgrade the night before I had HP and Intel engineers onsite to troubleshoot the interoperability issues - we were giving them one more chance to resolve the issue before we were probably going to switch to a different laptop and wireless card that had a proven record for working with LWAPP - like Thinkpad with atheros.
When the engineers arrived, the problem could not be reproduced - constant drops off the network and wild roaming (we have a very dense AP deployment (1232 & 1242 APs).
We recretaed the problem by downgrading a controller to 4.1.171.
I am extermely happy that we finally found a code to support the laptops and is also still compatabile with our 7921 phones. We have about 200 7921 phones we are deploying on 802.11a. We plan on keeping the data on b/g.
I am posting this just in case other people have similar issues.