Dave, your patch looks good to me.

Did you see the comment from Trevor on your first patch?

>> According to the sqlite docs (http://www.sqlite.org/threadsafe.html), the
default mode is 'serialized', which does the necessary locking for threads to
share a connection. Unless Python is overriding this to use one of the less
protected modes, it shouldn't be necessary to use extra locks around it.

This had prompted me to remove extra line on asking users to take care of synchronization.