Please clarify what do you mean with "updates continually".
While the previous version of the updater always had the "Update" button reading "Update", which confused some users assuming it was telling something like "an update is available" ( which is not what it does ), the current version of the updater will change the text of the button to "Check", to make it clear the ability of the button to be clickable, doesn't mean in any way an update is available or your version is old, just that you can run an update check at any time, even when you have the latest version, because what the button really does, is to verify all the files again, it won't disable itself "just" because it thinks you have the latest version, because if it did, you wouldn't have any way to restore missing/corrupted files without reinstalling.
If you see some files being always downloaded, that's also normal and of course is explained in the sticky thread about the offline installer: GSX jetway replacement files, airport services and GSX custom profiles for FSDT sceneries will always be downloaded no matter what, because we found it's way faster to do that, than checking thousands of small files each time.
This covers the updater when you start it from the "FSDT Installer" icon ( the program is the same ). When you start it from the "FSDT Live Update" icon, it will run with a reduced interface, which is designed to work without any input so, it will do an UPDATE *CHECK* of all products, downloading what is required and, again, if you see the files indicated above to be always downloaded, that's normal.
