@PLeoncini
When installing multiple versions I've seen problems with the Windows service best fixed by rebooting. I'm guessing you've already tried that.
You say it worked before with 2.0.2+16391. In case there's some sticky OS issue, can you confirm it works when you revert back to 2.0.2+16391 (available from the downloads page under "Additional versions")?
Some of our hardware interface code was improved in this build, although it wasn't meant to change anything functionally. If this is a true regression with 2.0.3, it'll probably create a crash dump. See if you have any *.dmp file under C:\ProgramData\Leap Motion or %AppData%\Leap Motion