Broken PHP Code Display

Hi,

Suddenly, my wordpress started to display broken php codes quoted in a post.

I use the Preserve Code Formatting plugin to show sample codes inside posts with the code and pre tags. And if I post a php code from the very beggining including the “<?php,” there gets a whitespace between “<” and “?(questionmark).” This prevents viewers from simply copy and paste the code.

It used to work fine. In fact, old posts are still displayed properly without the whitespace.

I tried to disabled recent installed plugins includeing WP-E-mail, WP-Print, Random Search Terms, WP-Cron, etc.. But didn’t help.

It would be greatlly appreciated if you have any kind of information.