Anyone trying to set up a Django app on Dreamhost where any model uses FloatField should be advised of this ticket. It kept me up a while.
The exception is a TypeError with value "float argument required".
It's not a Dreamhost-specific thing obviously. It's a MySQL 5.0.3+ specific thing. I'm just mentioning Dreamhost because that's how it bit me --- I was only testing with MySQL 4 on my laptop, and they have 5.0.16 installed. You can tell I'm new at this, testing on a different version of database than what will be used. Lesson learned.
The bug was actually in the mysql-python bindings. There is a fix from upstream, details are in the ticket thread.
(Thanks to malcomt for the help tracking it down.)
Update: Is it not strange that Dreamhost doesn't seem to have the python dev packages installed? It seems I may not be able to locally install the new mysql-python without locally installing um, python:
[centinela]$ python setup.py install --root=$HOME
error: invalid Python installation: unable to open /usr/lib/python2.3/config/Makefile (No such file or directory)