Pop-punk has become so earnest that even the common cold is enough to set off a lyrical lament. Singer Justin Pierre opens his band's sophomore release, Commit This to Memory sniffling about his runny nose and poor physical design. At least his other complaints are less lame: On ''L.G. Fuad,'' he surveys emotional wreckage resulting from ''social suicide'' (''Let me into the club 'cause I want to belong,'' he begs). And MCS' slick, soaring anthems ultimately unite the spirits of those who see themselves, like Pierre, as ''lifeless corners of this empty frame.''