OK so tried to fix this mono issue as per the bug thread http://dev.sourcefabric.org/browse/CC-5260 - which is closed, which this fault is most definitely NOT fixed - So that killed Liquidsoap - PID FAILED message. Tried restarting everything (playout, media-monitor, RabbitMQ, monit'd
the liquidsoap - nothing).

I put it back to what it was, the cue where it should be...but no amount of reboots or restarting playout, monitor, RabbitMQ etc etc would do anything.
so decided to reinstall Liquidsoap and AIrtime as a fresh install:

It got worse:

AIRTIME_STATUS_URL             = http://localhost:69/api/status/format/json/api_key/%%api_key%%
AIRTIME_SERVER_RESPONDING      = OK
KERNEL_VERSION                 = UNKNOWN
MACHINE_ARCHITECTURE           = UNKNOWN
TOTAL_MEMORY_MBYTES            = UNKNOWN
TOTAL_SWAP_MBYTES              = UNKNOWN
AIRTIME_VERSION                = UNKNOWN
OS                             = Ubuntu 12.04.2 LTS x86_64
CPU                            = Intel(R) Xeon(R) CPU E3-1230 V2 @ 3.30GHz
WEB_SERVER                     = Apache/2.2.22 (Ubuntu)
PLAYOUT_ENGINE_PROCESS_ID      = FAILED
PLAYOUT_ENGINE_RUNNING_SECONDS = 0
PLAYOUT_ENGINE_MEM_PERC        = 0%
PLAYOUT_ENGINE_CPU_PERC        = 0%
-- Displaying log file /var/log/airtime/pypo/pypo.log
-- 2013-07-11 04:22:38,043 INFO - [api_client.py : is_server_compatible() : line 220] - Unable to get Airtime version number.
--
-- 2013-07-11 04:22:43,047 DEBUG - [api_client.py : __call__() : line 134] - http://localhost:69/api/version/api_key/TLZZOY3Y7S44QKVM4DJQ
-- 2013-07-11 04:22:43,048 INFO - [api_client.py : is_server_compatible() : line 220] - Unable to get Airtime version number.
--
--
--
LIQUIDSOAP_PROCESS_ID          = FAILED
LIQUIDSOAP_RUNNING_SECONDS     = 0
LIQUIDSOAP_MEM_PERC            = 0%
LIQUIDSOAP_CPU_PERC            = 0%
tail: cannot open `/var/log/airtime/pypo-liquidsoap/ls_script.log' for reading: No such file or directory
-- Displaying log file /var/log/airtime/pypo-liquidsoap/ls_script.log
--
--
MEDIA_MONITOR_PROCESS_ID       = FAILED
MEDIA_MONITOR_RUNNING_SECONDS  = 0
MEDIA_MONITOR_MEM_PERC         = 0%
MEDIA_MONITOR_CPU_PERC         = 0%
-- Displaying log file /var/log/airtime/media-monitor/media-monitor.log
-- 2013-07-11 04:22:07,210 INFO - [Thread-1] [watchersyncer.py : __init__()] : LINE 19 - Created timeout thread...
-- 2013-07-11 04:22:07,210 INFO - [Thread-1] [airtime.py : init_rabbit_mq()] : LINE 36 - Initializing RabbitMQ message consumer...
-- 2013-07-11 04:22:07,214 INFO - [Thread-1] [airtime.py : init_rabbit_mq()] : LINE 48 - Initialized RabbitMQ consumer.
-- 2013-07-11 04:22:07,214 DEBUG - [Thread-1] [api_client.py : __call__()] : LINE 134 - http://localhost:69/api/media-monitor-setup/format/json/api_key/TLZZOY3Y7S44QKVM4DJQ
-- 2013-07-11 04:22:07,216 INFO - [Thread-1] [syncdb.py : reload_directories()] : LINE 49 - HTTP Error 403: Forbidden
--
--
-- There appears to be a problem with your Airtime installation.
-- Please visit http://wiki.sourcefabric.org/x/HABQ



Nope! *sigh* This version issue happened before, it's what Martin fixed with sudo dpkg-reconfigure rabbitmq-server RabbitMQ restart, and the other oddness of my server is monit failing so did that, although it's on a cron anyway: sudo monit monitor airtime-liquidsoap.

So radio silence again...