Addresses have been changed/improved for aiming assist. A new line has been added to config.txt:
72) If 0, Speeder will NOT target your previous target if you are not currently targeting a mob.
Currently, Speeder will target the most recent mob you have targeted via crosshair or proximity, the latter resulting in potentially unwanted behavior. I am working on improving this.
These changes require updating Speeder to version 30.