Ok i got confused right now, so this is the step i do

-Install Basecamp 4.2.4 at Win7 64bit
-Install MapInstall and then patch both of them
-Plug my SP2720 on Laptop, and open Basecamp (it can detect my SP2720)
-Right click to Install map on SP2720,and MapInstall program running
-There was a message "No unlocked map were found for this device"

Is there any step that i missing ?
Where should i put those NavNet .img files so MapInstall can recognize it ?