bwauth fails to parse something

The full error is

NOTICE[Sun Jan 15 12:45:02 2012]:Bw auth PID control disabled due to parse error.                                                                    
Traceback (most recent call last):                                                                                                                   
  File "/srv/bwauth/torflow.git/NetworkScanners/BwAuthority/aggregate.py", line 253, in __init__                                                     
    cs_bytes, re.M).group(1).split()                                                                                                                 
AttributeError: 'NoneType' object has no attribute 'group'

python 2.6.6 with Elixir-0.7.1 and SQLAlchemy-0.5.8