Ceph » rgw

hello,everyone...
nowadays i try to test Ceph s3 API. I have configure the ceph to run and can use it's POSIX API
and I have configured the apache2 and fastcgi... my ServerName is set to 192.168.0.17
when I type http://192.168.0.17 ,I can get the answer like this

<ListAllMyBucketsResult>
<Owner>
<ID>anonymous</ID>
<DisplayName/>
</Owner>
<Buckets/>
</ListAllMyBucketsResult>

But when I use the python API to create a bucket,it returns

boto.exception.BotoServerError: BotoServerError: 500 Internal Server Error
<Error><Code>UnknownError</Code></Error>

import boto
import boto.s3.connection
access_key = 'QWF4AVZEGZC6DS22ZNWH'
secret_key = 'K1NO+RfkpQnj1fqfHFnGWVNp8e+lGlBpgtd53QKq'

conn = boto.connect_s3(
aws_access_key_id = access_key,
aws_secret_access_key = secret_key,
host = '192.168.0.17',
is_secure = False,
calling_format=boto.s3.connection.OrdinaryCallingFormat(), )
bucket = conn.create_bucket('lollipop-dasdasdasdasd')
for bucket in conn.get_all_buckets():
print "{name}\t{created}".format(
name = bucket.name,
created = bucket.creation_date,
)

what is wrong? Thank you for your time...looking for your answers...