Regarding Port 30003 output, the 3.01 Beta version is currently outputing multiple "MSG,1" messsages for the same flight. "MSG,1" contains the flight number and it seems an unnecessary waste of output/time to keep re-outputing this information when it hasn't changed, even though it isn't syntactically incorrect to do so. Also, the goal as I understood it was to be more consistent with the output produced by SBS, which I am fairly sure only outputs one "MSG,1" for each flight.
SquawkBox uses the "MSG,1" to start logging the flight in its database and multiple "MSG,1" messages have meant that some flights could be missed or not shown for the correct length of time because they got re-initialised. I have however produced an update to the Beta 3.01 version of SquawkBox I produced two days ago to cope with this at
http://www.gfrost.co.uk/SquawkBox/SquawkBoxfor301Beta.zip. All flights that transmit a squawk code should now be included, albeit with a 5 minute delay.