The 4th parameter to format_text ($courseid_do_not_use) is used in several places in core Moodle code. I would suggest to fix it for Moodle 2.4.
Here are all the instances I've found outdated use in Moodle core 2.3dev (Build: 20120511):

question/editlib.php
1237: echo format_text($category->info, $category->infoformat, $formatoptions, $this->course->id);

blocks/rss_client/block_rss_client.php
253: $r.= format_text($description, FORMAT_HTML, $formatoptions, $this->page->course->id);

lib/filelib.php
1927: $output = format_text($text, FORMAT_HTML, $options, $COURSE->id);
1937: $output = '<pre>'. format_text($text, FORMAT_MOODLE, $options, $COURSE->id) .'</pre>';
2069: $output = format_text($text, FORMAT_HTML, $options, $COURSE->id);
2079: $output = '<pre>'. format_text($text, FORMAT_MOODLE, $options, $COURSE->id) .'</pre>';

lib/weblib.php
1399: return trim(format_text($intro, $activity->introformat, $options, null));

mod/workshop/form/rubric/assessment_form.php
95: format_text($definition, $definitionformat, null, $workshop->course->id), $levelid);
161: format_text($definition, $definitionformat, null, $workshop->course->id), $levelid);

mod/forum/lib.php
2979: $formattedtext = format_text($post->message, $post->messageformat, $options, $course->id);
3355: $postcontent = format_text(forum_shorten_post($post->message), $post->messageformat, $options, $course->id);
3361: $postcontent = format_text($post->message, $post->messageformat, $options, $course->id);

mod/forum/rsslib.php
334: $item->description = format_text($message, $rec->postformat, $formatoptions, $forum->course);

mod/forum/search.php
266: format_text($post->message, $post->messageformat, $options, $course->id),

mod/forum/locallib.php
298: $formattedtext = format_text($post->message, $post->messageformat, $options, $this->get('course')->id);

mod/glossary/rsslib.php
104: $item->description = format_text($definition, $rec->entryformat, $formatoptions, $glossary->course);

mod/feedback/item/textarea/lib.php
211: echo format_text($item->name.$requiredmark, true, false, false);
256: echo format_text($item->name . $requiredmark, true, false, false);
290: echo format_text($item->name . $requiredmark, true, false, false);

mod/feedback/item/info/lib.php
244: echo format_text($item->name.$requiredmark, true, false, false);
320: echo format_text($item->name.$requiredmark, true, false, false);
352: echo format_text($item->name . $requiredmark, true, false, false);

mod/feedback/item/textfield/lib.php
199: echo format_text($item->name.$requiredmark, true, false, false);
245: echo format_text($item->name.$requiredmark, true, false, false);
279: echo format_text($item->name . $requiredmark, true, false, false);

mod/feedback/item/captcha/lib.php
142: echo format_text($item->name.$requiredmark, true, false, false);
193: echo format_text($item->name.$requiredmark, true, false, false);
268: echo format_text($item->name.$requiredmark, true, false, false);

mod/feedback/item/numeric/lib.php
257: echo format_text($item->name . $requiredmark, true, false, false);
339: echo format_text($item->name . $requiredmark, true, false, false);
405: echo format_text($item->name . $requiredmark, true, false, false);

mod/feedback/item/multichoicerated/lib.php
305: echo format_text($item->name.$requiredmark, true, false, false);
353: echo format_text($item->name.$requiredmark, true, false, false);
388: echo format_text($item->name . $requiredmark, true, false, false);

mod/feedback/item/multichoice/lib.php
320: echo format_text($item->name.$requiredmark, true, false, false);
423: echo format_text($item->name.$requiredmark, true, false, false);
514: echo format_text($item->name . $requiredmark, true, false, false);

mod/chat/lib.php
808: $text = format_text($text, FORMAT_MOODLE, $options, $courseid);
968: $text = format_text($text, FORMAT_MOODLE, $options, $courseid);

course/lib.php
2556: echo highlight($highlightterms, format_text($course->summary, $course->summaryformat, $options, $course->id));

course/info.php
57: echo format_text($course->summary, $course->summaryformat, array('overflowdiv'=>true), $course->id);