Reply to quick question for ableton users

ok so after searching for a production software that i like, (borrowed a friends laptop with both ableeton and cubase while he was away on holiday) ive decided on ableton. I purchased live 8, and have started with playing with mashups.

my question is: i have a track and an acapella that sound really good together, but the acapella is about half a beat out, not really noticeable at first but does drift and become more prominent later on, i have read that you can warp a track, would this help to fix my problem?

please bear in mind that i am a total noob to any sort of production, remix, or mashup and am more than willing to follow tutorials, just thought id ask before i go ahead and do something that may not help in the slightest.

cheers,
brian.