I tried your program with the newest version of LabVIEW, which is 7.1 and the crash did not occure. I got an error message instead, telling me that the remote PC was not accesible.
But it takes maybe half a minute until the error comes up, and until that time LabVIEW does does not respond to any action, but this seems to be more like a Windows problem.
In order to work around the problem, you might send a ping to the IP Address before you try to make a connection via Datsocket. You can use the SystemExec Vi to send the ping command programatically. With the help of string functions you can investigate the result and check if the server is responding or not.
Ingo Schumacher
National Instruments