[nerbert]

$string = preg_replace(/\[code\].*\[\/code\]/i, "", $string);

I think that'll knock them out of $string. Are you good with plugins?

EDIT: Wait a minute, let me work on that some more.

EDIT2:

Here we go (I think)

$string = preg_replace(/\[code\][\s\S]*?\[\/code\]/i, "", $string);

--------------- Added [DATE]1321771433[/DATE] at [TIME]1321771433[/TIME] ---------------

All wrong about that. What I posted would match bb code. You will need to match html for a code box

PHP Code:

$regexp = '/<div class="smallfont" style="margin-bottom:2px">Code:<\/div>[\s\S]*?<\/pre>/i';

$string = preg_replace($regexp, "", $string);