In 2.03 this code was introduced in comm.c

if (ZBX_MAX_RECV_DATA_SIZE < expected_len)

{ zabbix_log(LOG_LEVEL_WARNING, "Message size " ZBX_FS_UI64 " exceeds the maximum size " ZBX_FS_UI64 " bytes. Message ignored.", expected_len, (zbx_uint64_t)ZBX_MAX_RECV_DATA_SIZE); total_bytes = FAIL; goto cleanup; }

All my agents running a Zabbix 1.4 agent (running on a Fritzbox ADSL router with an ARM processor) become unreachable if I run a server with this code.
I have now deleted that code from the source of 2.05 and it's now running fine....