Life is Good walked me thru it and it worked. I was struggling, too. Try these steps... I'll help you if I can. <3
Potsie, download a signature to Photobucket - click the direct button to copy - go to "panel" at the top of the 4food page and at the right click 'edit signature' - from there click 'add signature' - click the little icon that looks like a photo with a mountain - click 'add from URL' - paste what you copied from photobucket into the body space - add a signature title in the top box (leave text signature at the bottom blank) - click 'submit' - make sure your new signature title is there with a dot in the circle & then click 'save'. Hopefully, I explained it right! Good luck.
That worked for me.
I need to add that the changes you make might not be immediate. I thought I had done something wrong because it didn't appear to work. But a few hours later all was fine.