I used a Midleburn XC duo CHAINSET last season and suffered terribly with the chain jumping off both rings and in both directions. This was a problem while racing XC and cost me a couple of placings on more than one occasion.
Also when the chain jumped off the large chainring away from the bike it also got stuck inbetween the crank arm and the ring itself, this took a couple of minutes to untangle losing valuable time. Obviuosly a rivet inbetween the ring and crank arm would stop this like the XT chainset I am running now already has. Check this out first!