Tunes dropping on the off beat when DJing in Live..any ideas

[Stampatron]

Firstly hello all!
New to the forum & fairly new to Ableton and Im very keen for some advice as I have a recurring problem in that on occasional tunes, despite being correctly warped (as far as I can tell, i.e beatmatched through metronome etc) they drop in the off beat/wrong beat no matter when they are triggered.....? It seems to be coming out of the same track however so no matter what track i select to mix in, it still drops on the off beat...
Any ideas or advice would be greatly appreciated as I have my first live set on friday and there are a couple tunes i want to play which wont behave!
Many thanks
Peace

[DiGiTaLFX]

Maybe a dumb question, but is the start point on the first beat of a bar?

[Stampatron]

yes in all the cases the start point is the first beat of the track. however after some fiddling since the first post i'm convinced that its the preceeding track that has the issues as nothing will mix afer the second breakdown.....it appears that the track in question comes in on the off beat after the second breakdown and thus throws out the timing as all the tunes will mix fine up until this point.....shame cause the second break is the bomb!
any ideas how to combat this please?