You should also try running 'Show ap monitoring contianment-info' for an AP that is having the problem. It will tell you if the AP is attempting to wirelessly contain any of the clients.
If you go through the WIP wizard, on step 5 make sure none of the auto protection mechanisms are enabled. Also click on the 'containment methods' link at the bottom of step five and you can verify that wired and wireless containment are disabled.
I would be surprsied if any of the WIP configurations were cuasing the client disconnects. WIP primarily focuses around keeping your clients on your network and off of neighboring/rogue networks.