Had the same prob with the brembos after a single track day, ebc turbo grooves on track or not, not so much dba 4200s or smth but they didnt last long anyway, dixcels really bad at times but ok after a track day and even performance friction when brand new.
alex was right about the pad deposits since end of the track day we did at knockhill they where fine.
you can always remove them and go over them with thin sand paper and break cleaning spray. then bed in again. should be fine.