Hi @Anonymous, and welcome to myFICO!
I've moved your post to a new thread since the thread you posted to is about an old glitch that has since been resolved.
The issue you're having is due to your rank; you won't be able to add or edit HTML in your signature until your rank is a few levels higher. Don't worry, though, it doesn't take long! 
In the mean time, if you would like a seedling or spade added I can take care of that for you (any other moderator can help as well).
--UncleB
myFICO Moderator