google app engine downloading datastore entity with db.ListProperty

Question

Using the following link:

http://code.google.com/appengine/docs/python/tools/uploadingdata.html#Downloading_and_Uploading_All_Data

I am creating an bulkloader to download a datastore entity that is defined as follows:

class ReportEntry(db.Model):
    """A report from a Jinx instance running in the field."""
    entry_type = db.StringProperty(required=True, choices=set(['machine_info',
                                                               'crash']))
    entry_date = db.DateTimeProperty(required=True, auto_now_add=True)
    instance_id = db.StringProperty(required=True)
    instance_id_human_readable = db.StringProperty(required=False)
    build_id = db.StringProperty(required=True)
    version = db.StringProperty(required=True)
    crash_text = db.TextProperty(required=False)
    machine_info = db.TextProperty(required=False)
    cpu_count = db.IntegerProperty(required=False)
    cpu_brand = db.StringProperty(required=False)
    os_version = db.StringProperty(required=False)
    physical_memory_mib = db.IntegerProperty(required=False)
    product_loaded = db.BooleanProperty(required=False)
    virtualization_advertised = db.BooleanProperty(required=False)
    driver_installed = db.BooleanProperty(required=False)
    cpuid_info = db.ListProperty(db.Key, default=None)

As far as the last field, cpuid_info, is concerned, how exactly setup the handling for that list property field?

Also, that list of keys is for another entity. Are the key values preserved when you download the datastore? The reason why is that I have an issue around this particular association in production that I cannot reproduce on my local instance.