Recently the listwork group made a change to archiving that means that urls will not change when the archives are regenerated:

http://lists.indymedia.org/pipermail/imc-tech-announce/2004/0701-bo.html

The list archives you have requested were archived privately. As part of this change, we have to make private archives available again. This has not yet been achieved. Your data is safe, do not worry, and please be patient. In the meantime, if you would like your archives made public again, please email listwork at indymedia dot org. When we have done this, we will make an announcement on the imc-tech-announce list.