Remove the sig.bin from the directory on the other machine and reactivate it. If you are using Stardock Central, you can right-click on the component and select the Activate w/logging option. If not, it'll prompt for activation. Enter the email address and serial you've previously used with it.
The activation is liberal, within reason. A sig.bin from one OS install will not work on another. But, you can install and activate on a reasonable number of machines during a given period before it gets upset.
Posting your serial to a web forum so dozens of people can try and glom onto it will make it upset.
Kris