I've played a lot in the past week (8-9 hours a day), always in the group and never had connection issues except when the servers crashed once.
We flew together with CMDR Coenen several times in the same sytems and always seen each other on radar and on screen.
Used the ingame text chat extensively which disconnected a few times yesterday.
When this happened I had to select him again in the friends list, restart text chat and then I was able to answer all the time.
Sometimes it took 30 seconds from hitting Enter till the message was actually sent though.
We are friends ingame and are both playing from Europe that may help the match making.
I play the game on Windows Vista that is not even supported btw but it is rock solid.
My cable speed is max. 240/20 Mbit/s (guaranteed 60/5).