Here's what you do with screenshots AND you must have the code in the picture below titled as "
VERY IMPORTANT NOTE"
Step 1:

Step 2:

Step3:

VERY IMPORTANT NOTE:
Make sure that the links you put in the Signature box(In Step 3) are in this format:

Also try make sure that you can view the signatures/banners by following the procedure below:
Bring your cursor on
My Dashboard (A drop box will appear) > Click on
Update Profile > The click on the
Preference tab > Make sure that
Show Video Avatars + Banner Signatures is clicked on.
I hope it works out now and you can put up a signature. 😃