re-index pb [ezmlm-browse 0.12]

Hello,

I would re-index my mailing list archives,
so I do :

 vpopmail $  ezmlm-idx -d /var/vpopmail/domains/hforge.org/itools
 vpopmail $

And when firefox pointed to mailing list archive's url (which is an 
ezmlm-browse),

http://archives.hforge.org/index.cgi?list=itools&cmd=threadindex&month=200807&threadid=hbjojhkkhdfkeabjgehi
I get this error
 *<type 'exceptions.IndexError'>*: list index out of range
      args = ('list index out of range',)
      message = 'list index out of range'

How can I do to solve this ?
And what should I find into dir/num ? (what is this 2 number xx:yy ?)

Many thanks by advance,
    Guillaume 

-- 
Guillaume Romanczyk
Itaapy <http://itaapy.com>             Tel +33 (0)1 42 23 67 45
9 rue Darwin, 75018 Paris              Fax +33 (0)1 53 28 27 88