manage.py runserver throws an ImportError with my appname, MacPorts issue on OSX?
Okay, so this is very bizarre and I don't know what happened... but here's what fixed:

I open terminal and bash isn't recognizing any commands (python, vi, etc)  
I restart machine, still not recognizing any commands  
I look at my $PATH and /usr/bin is missing  
I add /usr/bin to $PATH  
I open vi and modify my profile to add /usr/bin  
vi works, python works  
python manage.py runserver works  

How did /usr/bin get removed from my bash profile?
I've been developing a Django app for weeks locally on OSX 10.6.3. Recently, I rebooted my machine and went to start my development environment up.
Here's the error:

cm:myApp cm$ python manage.py runserver
  Traceback (most recent call last):
    File "manage.py", line 11, in  execute_manager(settings)
    File "/Library/Python/2.6/site-packages/django/core/management/init.py", line 360, in execute_manager
      setup_environ(settings_mod)
    File "/Library/Python/2.6/site-packages/django/core/management/init.py", line 343, in setup_environ
      project_module = import_module(project_name)
    File "/Library/Python/2.6/site-packages/django/utils/importlib.py", line 35, in import_module
      import(name)
  ImportError: No module named myapp  

I'm pretty new to Django / Python.
Digging around, it's possible that this might be due to MacPorts. Initially, I had a rough time getting Django up and running and I no longer remember if I'm using the Django from a MacPorts install or from easy_install. How do I tell? (I'd prefer not to reinstall everything).
Also, why is the camel casing in my app name gone in the ImportError message? When I search for "myapp" in my django project, I don't find it without camelcase anywhere.
And what causes MacPorts to work for a while but then break?
As a few other details, from settings.py:

INSTALLED_APPS = (
      'django.contrib.auth',
      'django.contrib.contenttypes',
      'django.contrib.sessions',
      'django.contrib.sites',
      'django.contrib.admin',
      'south',
      'registration',
      'pypaypal',
      'notifier',
      'myApp.batches',
  )