strange timing issue during playback

a strange issue started to occur recently with the timing of audio tracks i'm recording on a particular song. there seems to be some latency during playback. i checked through some of the old threads that deal with latency and have followed some of the suggestions from there. i turned down my i/o buffer to the lowest possible setting, lowered the processor buffer range to 'smallest,' and unchecked software monitoring. none of this has had any effect. my tracks all play back approximately half a beat off time. here's a picture showing an audio file where i just plucked a guitar string on the quarter notes (i have decent rhythm, so that's not the answer ):

http://www.spockwithabeard.com/community_uploads/boy_poet/tickedoff3.jpg

you can see how the timing is just a little off. i suppose i could alter the anchor or the start position, but i feel i shouldn't have to do this on every track. this occurs on ONE song only. anyone have any further suggestions? here's my set-up:

dual 2.0 ghz powermac g5

512 mb ram

motu 828 mkii

let me guess, you have effects on the master bus? say, an Ad-Limiter or something like that? plugins of that sort add a delay to the playback signal. if when you record new tracks you play along to that signal, you will end up with a recording which is synchronized to the delayed playback. when you play it back with the others, it will receive an extra dose of delay from the master bus effect and it will sound off time.

of course, it could be something else.

but that would be my first guess.

the solution is not to use any latency-causing plugins on the master bus.

no adlimiter...

but i did have a linear phase eq. i had it 'bypassed' so i totally forgot it about it. that solved the problem. thanks a ton!