There is no denying that WordPress is one very popular PHP application, and that its popularity is well deserved, but perhaps what is more important is that WordPress provides a lot of flexibility in the form of plugins. WordPress Plugins extend WordPress by adding custom features (which may not be for everyone). In fact many of the WP Plugins do seem to be very specific, but there are a select few which have universal appeal. If you just installed WordPress, then your next task is to probably install all of these plugins or at least one of them.
If all of a sudden your Quicktags buttons no longer insert tags in your WordPress Write section, then the problem could be related to one or more WordPress plugins that you have installed.
I started having problems with the more button, as well as a couple of other quicktags that my other plugins added.
I traced the problem down to the Contact Form plugin, which has an option to enable it’s own quicktag button. If I disable just the quicktag and not the plugin, all my other quicktag buttons now work, including the ones that my other plugins added!
If you are having a similar issue with WordPress, try disabling one plugin at a time to see which one is causing it.
One of the hardest things to do in WordPress posts, is to quote actual code easily. It seems WordPress is a bit too aggressive with auto-fixing your html and it always ends up being a hassle to post some simple code bits. This is perhaps why BBCode in forums is so popular, as it makes this much easier.
While looking up plugins for something else I ran across: CodeHighlight, which makes the process easier. With this plugin installed you simple wrap your code text with simple BBCode style brackets.
<a href="http://www.somelink.com">Some Link</a>
You can download the latest plugin from here.