I'm currently running 3 4404 Controllers with 4.1.185 code (planning on going to 220.127.116.11 this Thursday, any issues here?) All 3 controllers are housed in Tower1 connected to a 6500. Controller one takes the load of the AP's in Tower1. Controller two takes the load of the AP's in Tower2. Tower1's 6500 is connected to Tower2's 6500 via EIGRP, so all wireless traffic in Tower2 is actually using Tower1's network. Works fine right? Well, we had an issue last week in part of Tower2 (only part of it) where our voice SSID was dropping clients, the wireless signal never faltered, but the 7921 phones were losing connection to the call manager. So we checked out and later found some possible interference.. no biggie right? The next day we had more issues in this area and the interferer had been removed, but this time the 7921's were losing their wireless signal. No errors could be found anywhere. The other devices on data SSID's were working fine, just not the phones and their SSID in this area ONLY! The only thing we could think of was that we did bump the code on the 3560 for this area to 12.2.35SE5 to support the SFP CAB connection to a second switch. One of the techs decided to revert the code on the switch and walla, the SSID for the phones started working just fine and no issues. Now, to throw wrench to that thought process right as we were working this issue another call came in from down stairs away from that location saying they were having similiar issues. We checked it out and indeed, an AP on a completely different switch, an older 3524 actually, would allow clients on the data SSID connect but could NOT connect to the voip SSID. We even tested this again by putting a 7921 into the data SSID and it worked fine on THAT AP. However, again we could NOT get a phone to connect to the VOIP SSID. NO changes have been made to any of the controllers and all of our SSID's run WPA2-PSK AES. The 3524 for this area in no way connects back to the previous area we were having issues with. They all go back to the core, but the kicker is, we reset the 3524 switch for the heck of it and of course the POE AP's bounce as well and walla, the phone SSID starts working again? What the crap. These AP's are 1232G's for the most part in this building. Any idea what the heck can be going on???? Any why all of a sudden trouble area's show up, but AP's on the same controller in different area's have no issues what so ever?