Sample is 'out' by fraction of ms on first loop when intro'd

[snadge]

In Ableton i have some breakbeat samples playing, when i start playing the second one (which is same sample as first one but without effects too beef it up the first sample) it sounds weak because its a fraction of a millisecond out, BUT, its only on the first bar, once it repeats the bar from then on it falls back into place with the correct timing and sounds how I want it - it does not do this if i start the samples together either..its ONLY when the first sample is playing then the second one kicks in and only for first bar...

can anyone help with this?

thanks