export audio cuts of first seconds of recording

I’ve been using cubase LE A1 which came with my steinberg UR22Mk2 audio interface, along with ‘superior drummer’ and my Roland V-drums recoding just midi for a couple of weeks now. I’ve been exchanging music files with my guitarist friend in the states, demo-ing some new songs in advance of a recording session later this year. When I export to audio (in mp3) the resulting recordings always have a couple of seconds cut off at the start. Any idea why this is happening and how to avoid it?
Thanks,
Calumn.

Sorry folks I found it myself. The left cursor was mysteriously set around 2 seconds thus explaining why the mp3 export didn’t take it all.