Provided solution is working of course, but incoming chat message can be easily missed now, because its small icon in tray. So I will stick with "Show the chat window" option anyway.
I beg you LogMeIn to remove automatic focus steal of hamachi IM window with incoming message, instead of this I suggest to popup chat window minimized on task bar, and blinking. In such way it can't be missed, and is not stealing your focus (which is very annoing).
Also always make minimized IM window blinking when new message comes until its viewed (chat window focused by user clicking minimized window on taskbar).
Please, please, fix this focus stealing. We are using premium hamachi in our company for years and this stealing focus chat window is only bad thing I can say about this great program.