The autodl isn't working any more due the changes in the site. Please refer to this thread to learn how to fix and autodownload again. See Thread
Due the changes made in the site the autodl file isn't good anymore.
I made the needed modification and here you can download the file.
BIT HDTV tracker
After you download the file. Rename it to 'BIT-HDTV.tracker'
and put it in ~/.irssi/scripts/AutodlIrssi/trackers replacing the old one.
Until the file is updated on github I advice all seedbox users to grab this file.