re-read this topic please. it's not the same problem as you use 2.9 and the situation changes with a disabled interface. see the wiki link about CPU usage.
Normis, I have read that thread about the CPU already, believe me, if there's something that we could do to drop CPU usage on the router, I'd do it. We've tried many things.
The reason for my post was to inform you that I see similar things happening on 2.9.41 as well as the beta. Just running hotspot and userman, no rules, queues, etc. I've looked at the traffic in torch and there's nothing significant, only 2 wireless users assiciated at the time the CPU pegs 100%. One user has very low signal. He keeps getting disassociated due to weak signal. We've tried to limit anyone connecting below 5.5mbs but that hasn't worked either. If we disable wlan the cpu usage does drop, but of course that doesn't help us as it's a hotspot. I can't get a proper supout because the router is overloaded and either crashes or has to be rebooted. I'm trying again after removing ntp package, I couldn't get a proper supout file, what I did get I sent already to support. I was starting to wonder if there was something wrong with the board, but if others are having the same problem ???
The board was installed around 4 months ago.