Hi Rango, some improvements .. I've realized that I've to put the images not inside the article, but in "Images and links" section .. So, I've arranged images in articles in this way. Now something appears in the web page, but is the empty module qithout thumbnails and images (see printscreen).
Taking a look in the page's source code I've found this:
http://localhost/joomla/modules/mod_vina_camera_slider_content/libs/timthumb.php?a=c&q=99&z=0&w=939&h=489&src=http://localhost/joomla/images/articles/outside.jpg
that, I suppose, is the command to display the image .. I copy&paste this line in the browser and the response is:

A TimThumb error has occured
The following error(s) occured:

Could not find the internal image you specified.


Query String : a=c&q=99&z=0&w=939&h=489&src=http://localhost/joomla/images/articles/outside.jpg
TimThumb version : 2.8.10

But typing "http://localhost/joomla/images/articles/outside.jpg" in the browser returns the correct image.

Any idea?
TIA,
Andrea-

Dear Andrea,

It's very strange! I've tried to check as your case but don't see any problem.
Could you please try enter this URL in your browser and let me know what you see: http://localhost/joomla/modules/mod_vina_camera_slider_content/libs/timthumb.php?a=c&q=99&z=0&w=939&h=489&src=http://extensions.joomla3.info/images/phocagallery/slideshow/image-14.jpg

Best regards.

I've tried and I can see perfectly your image! Maybe is a problem related to the particular images? .. It seems to me that my local images haven't any "peculiarity", however I post you my image .. Thank you again.

Dear Andrea,

So this is not problem with Timthumb Class, it is problem with your image.
Could you please try open your article and let me know if you see your image display there?
Or could you please upload your site to the server, then give me link to your page?

Best regards.

Yes, of course the images display correctly in articles! I also used other modules similar to yours (but, honestly, less attractive) and all is ok.
Sorry, but I want to work a little bit more in local environment before putting it on server .. I will make other attempts to discover where is the problem.
Thank you for your support,
Andrea.

Strange, very strange .. it seems to me that the library, for misterious reasons, has some problems to work in the "localhost" environment. I've uploaded an image in another domain that I manage and I typed in the browser:
http://localhost/joomla/modules/mod_vina_camera_slider_content/libs/timthumb.php?a=c&q=99&z=0&w=939&h=489&src=http://www.roncadebasket1998.it/images/articles/20132014/camere.jpg
All is fine, the image is displayed .. but instead
http://localhost/joomla/modules/mod_vina_camera_slider_content/libs/timthumb.php?a=c&q=99&z=0&w=939&h=489&src=http://localhost/images/articles/camere.jpg
produces an error, even if the image exists (and in fact if I type "http://localhost/images/articles/camere.jpg") the image is correctly displayed.
Maybe when I put on server all will be fine, but is frustrating for me not have the possibility to test and prepare all offline...

Best regards