I think this solves my problem, I took away the -n from the launcher so
the command is just "/usr/bin/idle-python2.5". Now Idle does not show
the No subprocesses text, and when I press F5 the Python shell displays
a line with ====Restart====. I tested my case and the value change in
the imported module was recognised as expected. The launcher under
applications still gives the no subprocesses version.
But for other Ubuntu users the problem may persist, where does the
"/usr/bin/idle-python2.5 -n" come from?
I installed idle using System-Administration-Synaptic package manager,
where I selected Idle-python2.5 I don't know enough about it to say
whether the command comes from there or is interpreted somehow during
the installation, or some other way.
Thank you for your help so far, it makes my Python learning so much easier