Koos,
Remove 'Add Ctrl-Z' from the preferences. To do this, open the text file, go to Edit-->Preferences. Disable 'Add Ctrl-Z'. Enable 'save preferences' if you don't want to add this character to further text files. Otherwise it will work for the currently open text file only. Before saving the file, remove the current Ctrl-Z symbol. Same thing you can do for the prg file. Remember that you cannot access the preferences until you open the file.

Yashodhan.