Textile comments fix
As of the 4.0.2 release of Textpattern, which for the most part, is really quite good, there's an issue with how Textile parses comments. Textile is Textpattern's built-in syntax handler, to create links and such, without using HTML. The reason this is beneficial in comments is to keep people from inputting HTML directly, and possible exploiting vulnerabilities in your website.
In the days before the 4.0.2 release, a light version of Textile was made available to people who wanted to leave a comment on a Textpattern site. This allowed them to make hyperlinks, add boldness or italics to text, do strike-through effects, etc. Some TXP users felt this wasn't enough, and advocated for full Textile handling, so that people would be able to use blockquote and the like.
While this is all well and good, the 4.0.2 changes also opens the door for any other syntax that Textile is able to handle. This means that if people want to use your site headers, they can, even if you've styled your H1 to be your company logo or whatever. It also allows for people to input tables within their comments, something a CSS purist might frown upon.
Luckily, the person who goes by the username SHARK on the Textpattern forums came up with a solution. It involves hacking your txplib_misc.php file, in the /textpattern/lib/ directory. In case you're not comfortable with hacking the PHP, but still want to force comments to behave correctly, you can download a replacement file here…
402-textile-fix.zip (12 KB)
You will just need to replace this file with the old one. Though I have had no problems at all with this fix, I recommend backing up your old one, just in case. Please note, this is only for the Textpattern 4.0.2 release.