There's something more to that opcode. Not sure what it is but it seems to be more active for this user on my server.... sent serveral times a second which is more than your 15 minutes and is causing lag for them. I wouldn't recommend that opcode.
Code:
[08.19. - 08:36:32] [CLIENT__NET_ERR] Ikeren: Unhandled incoming opcode: [OpCode OP_Unknown (0x6a5f) Size=8]
[08.19. - 08:36:32] Unable to convert EQ opcode 0x6a5f to an Application opcode.
[08.19. - 08:36:32] [CLIENT__NET_ERR] Ikeren: Unhandled incoming opcode: [OpCode OP_Unknown (0x6a5f) Size=8]
[08.19. - 08:36:32] Unable to convert EQ opcode 0x6a5f to an Application opcode.
[08.19. - 08:36:32] [CLIENT__NET_ERR] Ikeren: Unhandled incoming opcode: [OpCode OP_Unknown (0x6a5f) Size=8]
[08.19. - 08:36:36] Unable to convert EQ opcode 0x6a5f to an Application opcode.
[08.19. - 08:36:36] [CLIENT__NET_ERR] Ikeren: Unhandled incoming opcode: [OpCode OP_Unknown (0x6a5f) Size=8]
[08.19. - 08:36:36] Unable to convert EQ opcode 0x6a5f to an Application opcode.
[08.19. - 08:36:36] [CLIENT__NET_ERR] Ikeren: Unhandled incoming opcode: [OpCode OP_Unknown (0x6a5f) Size=8]
[08.19. - 08:36:36] Unable to convert EQ opcode 0x6a5f to an Application opcode.
[08.19. - 08:36:36] [CLIENT__NET_ERR] Ikeren: Unhandled incoming opcode: [OpCode OP_Unknown (0x6a5f) Size=8]
[08.19. - 08:36:37] Unable to convert EQ opcode 0x6a5f to an Application opcode.
[08.19. - 08:36:37] [CLIENT__NET_ERR] Ikeren: Unhandled incoming opcode: [OpCode OP_Unknown (0x6a5f) Size=8]
[08.19. - 08:36:38] Unable to convert EQ opcode 0x6a5f to an Application opcode.
[08.19. - 08:36:38] [CLIENT__NET_ERR] Ikeren: Unhandled incoming opcode: [OpCode OP_Unknown (0x6a5f) Size=8]
[08.19. - 08:36:38] Unable to convert EQ opcode 0x6a5f to an Application opcode.
[08.19. - 08:36:38] [CLIENT__NET_ERR] Ikeren: Unhandled incoming opcode: [OpCode OP_Unknown (0x6a5f) Size=8]
[08.19. - 08:36:38] Unable to convert EQ opcode 0x6a5f to an Application opcode.
[08.19. - 08:36:38] [CLIENT__NET_ERR] Ikeren: Unhandled incoming opcode: [OpCode OP_Unknown (0x6a5f) Size=8]
[08.19. - 08:36:38] Unable to convert EQ opcode 0x6a5f to an Application opcode.
[08.19. - 08:36:38] [CLIENT__NET_ERR] Ikeren: Unhandled incoming opcode: [OpCode OP_Unknown (0x6a5f) Size=8]
[08.19. - 08:36:38] Unable to convert EQ opcode 0x6a5f to an Application opcode.
[08.19. - 08:36:38] [CLIENT__NET_ERR] Ikeren: Unhandled incoming opcode: [OpCode OP_Unknown (0x6a5f) Size=8]
[08.19. - 08:36:38] Unable to convert EQ opcode 0x6a5f to an Application opcode.
[08.19. - 08:36:38] [CLIENT__NET_ERR] Ikeren: Unhandled incoming opcode: [OpCode OP_Unknown (0x6a5f) Size=8]
[08.19. - 08:36:39] Unable to convert EQ opcode 0x6a5f to an Application opcode.
[08.19. - 08:36:39] [CLIENT__NET_ERR] Ikeren: Unhandled incoming opcode: [OpCode OP_Unknown (0x6a5f) Size=8]
[08.19. - 08:36:40] Unable to convert EQ opcode 0x6a5f to an Application opcode.
[08.19. - 08:36:40] [CLIENT__NET_ERR] Ikeren: Unhandled incoming opcode: [OpCode OP_Unknown (0x6a5f) Size=8]
[08.19. - 08:36:42] Unable to convert EQ opcode 0x6a5f to an Application opcode.
[08.19. - 08:36:42] [CLIENT__NET_ERR] Ikeren: Unhandled incoming opcode: [OpCode OP_Unknown (0x6a5f) Size=8]
[08.19. - 08:36:42] Unable to convert EQ opcode 0x6a5f to an Application opcode.
[08.19. - 08:36:42] [CLIENT__NET_ERR] Ikeren: Unhandled incoming opcode: [OpCode OP_Unknown (0x6a5f) Size=8]
[08.19. - 08:36:42] Unable to convert EQ opcode 0x6a5f to an Application opcode.
[08.19. - 08:36:42] [CLIENT__NET_ERR] Ikeren: Unhandled incoming opcode: [OpCode OP_Unknown (0x6a5f) Size=8]
[08.19. - 08:36:42] Unable to convert EQ opcode 0x6a5f to an Application opcode.