FM10 Freezing after sending TCP Socket requests via Groovy script

I'm evaluating Scriptmaster as part of a potential solution for a client project. We have written a one line script to test whether we can send TCP Socket requests out of FileMaker to a hardware device (remote power switch). Our FM script is actually 2 lines (the first simply set's the "ip" variable - the second is as follows:

EvaluateGroovy( "s = new Socket(ip, 80).withStreams { input, output -> output <<'TCPCommandGoesHere'; r = input.getText();}" )

This works for a few minutes (TCP command is sent and the remote device responds with either 'ON', 'OFF' or 'BUSY') but then FileMaker 10 (Trial version) freezes and will accept no further input requiring a restart. We've already written test scripts outside of FileMaker (in Python and Ruby) and they are not freezing.

Ideally we'd like to solve the problem of the script freezing FileMaker as we'd prefer to execute this project within FileMaker and not have to develop an external web app.

Are we doing anything obviously wrong ?