i just recently started using poker tracker and am also labeled a SLAP. it was my understading the aggresive referred to after the flop and the passive was overall, including preflop aggression. in my case, playing low pot limit/no limit ($25 max), i tend to call with speculative hands (suited connectors and suited aces) in early position, especially if the table has a low PFR. it's probably a leak, but i've convince myself it's the nature of low limits. your case may be different with more preflop aggression and less postflop, but analyzing the "more details" page in pokertracker will give you a better idea of where you might want to make adjustments.