Thanks for your replies, I managed to solve the light issue, tho it still doesn't look natural.
I am still having troubles with teh shadows though...
I am attaching a photo of the scene that I'm working on.
Please notice that the big tree is visible but does not recieve the amount of light that the environment recieves from the moonlight (directional light, blue color).
Also, both the tree and the plants don't cast any shadow and I have double checked and all the shadow parameters you've instructed me to check are on.
In addition, I am having a problem understanding how to fix the porch light.
As you can see, there is a lit light bulb on the porch wall with one point light right ahead of it.
What happens there is that the light actually lights the entire scene and is not shown too well to my taste.
So, first, is there a way to limit the radius of a light? I just want the bulb to light the balcony and some of the ground nearby, but it actually reaches the front part and the hills on the back...
Second, is there a way to create a more yellow intense light from that bulb? is using point light the right choice for a bulb like that?
Thank you again, you are saving me!! :p