first question from newbie. Haven't needed to post a question for months now -- so many great answers already posted. I am stuck on this one, though.
Developing on a Mac, Python 2.7, Django with the django-nonrel project, GAE datastore. Up to and including GAE SDK 1.6.3, all goodness. After upgrading to GAE SDK 1.6.4, noticed 3 strange things:
- Dev server (python manage.py runserver) fails immediately with "Error: No module named webob." No other errors or output. I rooted around under /usr/local/google_appengine/lib/... and, indeed, no module named webob. There are two close matches -- webob_0_9 and webob_1_1_1. I made a symlink webob -> webob_1_1_1 to get past the error. 
- Startup messages from the dev server include an INFO: message that the SDK version is later than the advertised version. Google has 1.6.4 on their download site, so not seeing how my 1.6.4 is later than the latest. 
- Django's syncdb command (python manage.py syncdb) will no longer create the .gaedata/datastore file. It says it's creating tables, it prompts me for the superuser creds, it even says it installed a bunch of objects from my fixture file. It gives no errors, but when it completes, it has done none of these things -- the .gaedata/datastore file doesn't even exist. 
Prior to 1.6.4, syncdb worked great, including loading fixture data. I tried starting a fresh project with only bare bones files in it and a simple model (one class having one field) to see if some complexity I had introduced might be the cause of the problem. Even in simple-land, syncdb wouldn't create the datastore.
My only solution was to fall back to GAE SDK 1.6.3 -- everything works once again. Anyone else seeing similar symptoms with SDK 1.6.4? Are there obvious diagnostic steps I should be taking?