When I run:

$ s3cmd ls s3://v2_Antibody_2JEL_b/

I am getting the following error:

Problem: IndexError: list index out of range
S3cmd:   0.9.9
Python:  2.6.1 (r261:67515, Mar 18 2009, 13:18:47)  [GCC 3.4.6 20060404 (Red Hat 3.4.6-9)]

Traceback (most recent call last):
  File "/usr/local/bin/s3cmd", line 1562, in <module>
  File "/usr/local/bin/s3cmd", line 1542, in main
  File "/usr/local/bin/s3cmd", line 88, in cmd_ls
    subcmd_bucket_list(s3, uri)
  File "/usr/local/bin/s3cmd", line 118, in subcmd_bucket_list
    response = s3.bucket_list(bucket, prefix = prefix)
  File "/usr/local/lib/python2.6/site-packages/S3/S3.py", line 136, in bucket_list
    uri_params['marker'] = self.urlencode_string(list[-1]["Key"])
IndexError: list index out of range

Note that the command:

$ s3cmd info s3://v2_Antibody_2JEL_b/

returns a positive value:

s3://v2_Antibody_2JEL_b/ (bucket):
   Location:  any
   ACL:       popone: FULL_CONTROL