Hi EfeB06,
I checked the url of the image you were linking to in your signature and it seems like it's either broken or expired, your best bet is to reupload your image or upload it to a different service such as http://www.imgur.com.
Make sure you're copying a
direct link to the image ending with an image extension such as .jpg .gif and .png from your image hosting service and featuring it in your BBcode IMG tag like this:
Code
[IMG]http://www.yourimagehostingsite.com/yourimage.jpg[/IMG]