JC, you have to click on Show Signature every time you post. The default is to NOT Show Signature every time, so you have to tell it, patiently, “Yes, please, I want my signature to show this time, too.”
Also, there’s an interesting little–not quite a bug, but a “thingie”, where if you click Show Sig, and then Preview Reply, it will un-click Show Sig while it’s Previewing your Reply, but without telling you (no “bwwahhh-hah-ha ha ha, watch me un-click this feeb’s Show Sig! Ha ha ha ha!”)
So if you go directly from Preview to Submit Reply, and don’t click Show Sig (again!) your post won’t have a sig.
We all just get used to it. [sigh] They say you can get used to anything.
And, er, like Picmr said, you DO have a sig in your Profile, right?
Click on Edit Profile up here in the top right-hand corner, put in your user name and password, the Signature box is way down at the bottom.
You can use Preview Reply, diabolically enough, to preview your signature, so you don’t have to go public with it until you’re ready.