I also have this problem. However, the problem is with various laptops (macs and PCs) and is intermittent.
WLC version: 8.3.133.0
*Dot1x_NW_MsgTask_1: Mar 26 10:53:13.639: [PA] dc:a9:04:7d:4c:29 Sending EAP Request from AAA to mobile dc:a9:04:7d:4c...