a. Everything is picked perfectly from the db with following SQL:
SELECT `countries` FROM `countrytable` WHERE `continent` = '[cb_continent]' ORDER BY country

b. Two of the country lists are not picked from the db with following SQL:
SELECT `countries` FROM `countrytable` WHERE FIND_IN_SET( `continent`, REPLACE( '[cb_continent]', '|*|', ',' ) ) > 0 ORDER BY countries

I've no idea what the value of [cb_continent] is. If one of the values selected contains a comma or |*| or the continent column contains a comma it's not going to work right. All I can provide you is simple SQL examples. The rest is left to you. I've no idea what your database structure is or the values you're using.