There was a bug with the movement speed hack in the most recent version of Speeder. This has been corrected, but you will need to download the new version (version 2) if you want the movement speed hack to work correctly.
Addresses have been updated on the server, and Speeder is ready to use. If you already own a copy of Speeder (i.e. version 1), you can simply log in and start playing. However, if you do use the movement speed hack, make sure you update to version 2 via -download or with the link here. (Just replace the Speeder executable.)
If you are a new user and/or wish to use the movement speed hack, the link to download/update the program is here: