SSL_read failed in a system call (-1), TLS session fails

Hello all, We're running FreeRADIUS 1.1.3 with EAP/TTLS (openSSL 0.9.8d) on Red Hat 5.1. The server will come up and process clients for a few days, but, every now and then it begins denying all auth-requests with the following error: Error: rlm_eap: SSL error error:1408F119:SSL routines:SSL3_GET_RECORD:decryption failed or bad record mac Error: rlm_eap_tls: SSL_read failed in a system call (-1), TLS session fails. Auth: Login incorrect: [host/user/<no User-Password attribute>] A restart makes the server happy and it goes back to properly auth'ing clients. Thanks in advance!