We have a dual core made up of 2 6513's. In 6513#1 we have WiSM#1 which we have had for sometime now. We have added a 2nd WiSM in 6513#2 for redundancy purposes also we are going to be re-configuring the WiSM in 6513#1 to more match that of the new WiSM in 6513#2. We have installed the new WiSM and failed over the AP's from 6513#1 so we can re-configure it's WiSM. The failover went great and no issues, with the exception that a web application or two didn't function from wireless clients and users were having issues getting to some mapped drives. The only difference from the new WiSM config vs the old WiSM is that on the old WiSM the AP's were in the same VLAN as the controller management interfaces. Now with the new WiSM it's configuration has the controllers AP mgt interfaces ip addresses in a different VLAN from the AP's, we are doing this based on Cisco best practices. If we revert the AP's back to the original WiSM/controllers the PC's where they are on the same vlan/subnet the applications and shares that were having issues the other way work. We have placed a call with Cisco TAC and they say our configs look good and we even sent them some packet captures and they said everything looks normal. The wireless clients can ping and resolve the server hosting the application database just fine.