http://moodle.org/mod/forum/discuss.php?d=65204

Joseph Rézeau suggests the fix:

Solution: In file moodle/mod/quiz/edit.php, towards line 185, replace:

$form->name = get_string('random', 'quiz') .' ('. $category->name .')';

with

$form->name = get_string('random', 'quiz') .' ('. addslashes($category->name) .')';

which is right. I'll apply it.