I reproduced this after removing all plugins except SyntaxHighlighter Evolved version 2.3.8. I'm only using the HTML editor, not the Visual one.
- Goto a post that is published.
- Added a block like `[code lang="js"]
- Click update
- View the post. Notice it is correctly formatted.
- Edit the post again -- making a random change outside the
- Click preview.
- Notice that the Syntaxhighlighted section is wrapped in
<span>and the link is wrapped in
- View the post. Notice it is still correctly formatted.
- Click update.
- View the post. Notice it is now messed up like the preview was.
Sometimes, it'll start working again, but I'm not sure what triggers it. It's very annoying.