Yes, this is a known bug. Sorry for that.
Please install 0.9.9.53 first and import the senders as usual. Then go to Spamihilator's configuration directory (http://wiki.spamihilator.com/doku.php?i ... onfigfiles
) and delete the file "senders.db" if it is there. This is the file used by version 1.0 to store senders. It should be empty in your case. So, it's safe to delete it. After that install version 1.0. Your senders should now be available again.