Hi,
I'm under the impression that the 4410n doesn't have much capablity along the lines of debugging. Correct me if I'm wrong.
Are you seeing anything in the logs of the ap? I think syslogging is disabled by default, so you may want to turn that on and keep an eye out for events when the issue occurs.
You might want to consider in investing in one of these:
http://www.cacetech.com/products/airpcap.html
This is a relatively inexpensive way to capture promiscuous wireless traces. It would likely help clarify the issue if you were able to capture a wireless trace (on one of the problematic client's channel) when the issue was evident.
Sorry, wish I had more to offer. As you already know, if you can't run debugs or capture traces you're pretty much shooting in the dark.
hth
jeff
