Sync issues when exporting OMF from FCP

Hi everyone, bit of a strange one this but people on this forum have been very helpful in the past so I thought it would be worth asking. I have a director friend who has sent me an OMF of the 25 minute short film he's been working on, he also sent me a locked cut of the film as an .mp4 with a stereo mixdown of the audio.

When I import the OMF, video file and mixdown audio into my DAW (cubase) some parts of the OMF are out of sync with the mixdown audio track, there will be a few clips in sync then a few out of sync I can't seem to see any pattern to it. It always seems to be out by 2 frames and roughly half the clip are out of sync.

I've looked around on the net and found a few people who think it may just be a bug of FCP but I've not had any solutions or even a definitive answer as to what's causing this.

Has anyone else run into these problems before?