Duplicate Licence ID's Detected

I have one copy of FSX deluxe for my desktop and one for my laptop so i can host a server and log in to it from my pc. The first attempt i tried was to use the one copy of fsx and activate it on both computers, this activated with out error. Once i connected to my laptop over the LAN an error msg popped up on my desktop stating that Duplicate licence id's were detected. I then bought another copy of FSX and uninstalled FSX on the laptop then re-installed the brand new copy and activated it online with out any problems, however the error or duplication still appears... Did i not remove it completely? not sure where these licence keys are stored but its not a duplication anymore. Very fustrating.