building mac.app for xcode_iphone- symbol(s) not found

I am currently trying to build a mac app and im getting this 1 error thats has had be stumped...

its when

linking ../../../tgb/gamedaa/t2dproject/tgbgame.app/contents/MacOS/tgbgame (1 error)
(X) "mode7AddParticle(t2dParticleEffect"), reference from:
ct2dParticleEffectmode7AddObjectcaster(SimObject*, int, char const**)in t2dParticleEffect.o
symbol(s) not found
collect2: ld returned 1 exit status

build failed 1 error, 36 warnings... blah

well i have tried to fix this a lot of ways.. no luck... t2dParticleEffect.o is in my xcode build... so when i add it to my project i get the double reference/symbol fail error gcc 4 blah... can't figure this out for the life of me any one got any ideas?

dark