Just looked into it, and it's due ot permissions:
Traceback (most recent call last):
File "/usr/share/kabikaboo/src/kabikaboo.py", line 1231, in save_document_callback
File "/usr/share/kabikaboo/src/file.py", line 110, in save
if self.save_to_file_pickle(self.working_file, document):
File "/usr/share/kabikaboo/src/file.py", line 293, in save_to_file_pickle
output = open(filename, 'w')
IOError: [Errno 13] Permission denied: '/home/aidave/Documents/Scripts/Creation Myths/Kabikaboo/CreationMyths-80.kaboo'
So it should be giving the user a warning.