I fixed it for myself with changing core/string_api.php:68

from:
preg_match_all("/<pre[^>]?>(.|\n)?<\/pre>", $p_string, $pre1);

to:
preg_match_all("/<pre[^>]?>(.|\n)?<\/pre>|<ol[^>]?>(.|\n)?<\/ol>/", $p_string, $pre1);

Description should have been:
As I see it >ol> and >ul> should be displayed in a similar maner to >pre>,
i.e. without ' ' -> '&nbsp;' or '\n' -> '>br>' inside the tag.

Anything I can do to assist?

Patches againt Git are welcome. http://docs.mantisbt.org/master/en/developers/dev.contrib.html

Yeah, please attach a patch based on git master. Current code differs.

--------------------
Similar to nl2br, but fixes up a problem where new lines are doubled between
 tags.
additionally, wrap the text an $p_wrap character intervals if the config is set
function string_nl2br( $p_string, $p_wrap = 100 ) {

$output = '';

$pieces = preg_split( '/(<pre[^>]>.?<\/pre>)/is', $p_string, -1, PREG_SPLIT_DELIM_CAPTURE );

if( isset( $pieces[1] ) ) {

foreach( $pieces as $piece ) {

if( preg_match( '/(<pre[^>]>.?<\/pre>)/is', $piece ) ) {

$piece = preg_replace( "/<br[^>]*?>/", "", $piece );
            # @@@ thraxisp - this may want to be replaced by html_entity_decode (or equivalent)
            #     if other encoded characters are a problem
            $piece = preg_replace( "/&nbsp;/", " ", $piece );
            if( ON == config_get( 'wrap_in_preformatted_text' ) ) {
                $output .= preg_replace( '/([^\n]{' . $p_wrap . '})(?!<\/pre>)/', "$1\n", $piece );
            } else {
                $output .= $piece;
            }
        } else {
            $output .= nl2br( $piece );
        }
    }
    return $output;
} else {
    return nl2br( $p_string );
}
}