Hi!
I’m new to JME and just started beginner tutorials.
When trying out the first one, I noticed that the default control (WASD) is not working at all if I keep JME3 at default settings - you can see that pushing a button has a very very minor effect (barely noticeable), but definitely not what should happen. Also, my PC (I guess my graphics card) is making a strange squeaky sound when the application is running. Mouse control works well though.
When I turn on VSync on the other hand, all the keyboard and mouse control works properly, but the framerate goes down to a very low value resulting in a lot of lagging. No noise from my PC with VSync enabled.
Any clue what could cause these problems? I can’t really work with it this way, and enabling VSync is surely not a proper solution.
I just updated my graphics card drivers (GeForce GTX 260), but it didn’t change anything.
The squeaking you’re hearing is likely the capacitors in your graphics card being stressed. This is well documented on higher end GPU’s when they’re stressed. It is safe and shouldn’t be a cause for concern, except for the sound driving you mad 
As for the keyboard movement. This is due to inaccuracies in the timer when super high frame rates are achieved. As you add objects to the scene and cause it to render slower, your controls will work normally again. What you’re seeing with vsync enabled is a lowered framerate and the timer behaving normally again. This is a known issue and their are ongoing discussions about solving it.
You can solve 2) by getting an external (e.g. USB) audio interface instead of using the internal sound card of your computer.