Sorry to ask, and I don't mean to be condescending, but have you used maya / python for a long time?
If you have, then this might be a software bug. You could try resetting your preferences to default, or failing that re-install Maya.
If you are new to Maya / python it could be something more straightforward.
You could check your script editor's History tab to make sure that nothing is getting suppressed.
Also, python will not appear in the script editor by default, as Maya natively runs on Mel commands. If you want to view any outputs from python you will need to run print statements, or cmds.evals() and the like.
If you already know all this, sorry for telling you how to suck eggs ><
