This has been fixed. It was due to a CSS setting in /css/common.css, which means it was visible in all of the perlmonks "themes" (not including "No Theme", which has no CSS).
The specific CSS code was:
So if you decide you want to dink with the appearance of a reply when it is the displayed thread "root", use div.notetext.
Thanks for noticing this, tye.
Update: On a related note, the styling (font size setting) of the "Reputation" part of note display — that's the part that shows the ++ and -- buttons, or the current reputation if you've already voted — has been changed from a hard-coded <font size="1"> to CSS. The styling in common.css is:
in case you'd like to override that in your Display Settings (or set it to something at all, if you're using No Theme).
What is the sound of Windows? Is it not the sound of a wall upon which people have smashed their heads... all the way through?
In reply to Re^3: Size of text in replies when showing threads (backward)