Howdy,
Our forums are just a little bit clunky, so there are a few bugs and issues. Not to worry though! We are squishing those nasty bugs in the meantime!!
In order to attach a signature to your post you must first create or begin replying to a thread. Then at the bottom(under the "Preview" and "send" options) there will be an "options" window. You must check the box beside "Attach Signature" then you're all set! Unfortunately there isn't an option available to save that setting, so you will have to constantly check that box in order to attach your signature to your posts.
We are sorry. ):