jespah wrote:I checked your account, Thomas, and it's set to "always attach my signature" so that's not a problem. Is it possible that you're accidentally unchecking the Attach signature (signatures can be changed in profile) box when you either post or edit a post?
It will not change automatically with an edit, but you might be accidentally unclicking, e. g. a stray click of the mouse and that might explain it.
Thanks for checking, Jespah. I guess it's possible that I accidentally uncheck every now and then. But wandeljw's observation is reproducible. I have observed the signature in my posts since I started this thread. And as it turns out,
every time I edit, the signature goes away.
Every time I don't edit, the signature stays. I very much doubt that I accidentally uncheck it every time I edit, and never uncheck it every time I don't edit.
But at least we've made progress. The disappearance is no longer "unpredictable".
EDIT: The signature line was there after I first submitted this post. Now I deliberately edit to see if the "attach my signature" checkbox is unchecked, and what happens with the post after I submit again. Looking at the list of checkboxes beneath the editing window, I notice that there no longer is an option "attach my signature". The option is there when I start a new post, but not when I edit one.