i would think if you're playing tight and fairly aggressive, then you should NOT be a consistent loser. not sure it would make you a winner, but certainly not a loser.

a few things i'd check. are you really playing as tightly as you say?? or are you starting to creep looser when the cards go cold??? and then you don't tight back (shouldn't have looosened anyhow).

from what i've seen, complete killers are A-medium kicker offsuit, and people going for gunshot straight draws. turn and river are very expensive.

the other thing i found from reading SSME miller, king yao and some others is that you have to be aggressive in building pots. are you raising enough??

i think the micro-limit forum in here has FAQ with lots of stuff on VPIP, PFR, % going to showdown, % win at showdown. get an idea if you are even playing that.

i don't know sklansky top 5 hand groups (i've seen them, i just don't remember), but i have to figure tons of those hands can not be played in medium and especially late position.