Ive been browing ang veiwing the dds file in the c3 folder for this problem for age now and ythin the answers simple , im pretty sure the fire works grahpics can be found in the foldr marked up as: zf2-e248. what i did was to edit each dds file to blank graphic and save them. Im not sure this will stop the lag but i do hope so as i'll be finding out tonight on my OLD relic pc.
Good luck to you to!