How do I stop Moviestorm from updating automatically?

Find your installation:
PC: Moviestorm normally installs to C:/Program Files/Moviestorm-1.4
or to C:/Program Files (x86)/Moviestorm-1.4

Mac: In Applications, right click on and select 'Show Package Contents', then browse to Contents/Resources

Within the installation folder above, look in the 'boot' folder.
PC: Open in a text editor
Mac: Open in a text editor

Look for the line
Change it to
This will prompt you to update, when updates are available.
Or change it to
This will not check for updates at all.