Circles / roundabouts have 2 lanes for a reason > to help the flow of traffic. The outside lanes are for immediate exit and in most cases shouldn't be used to go around more then one exit (an exception would be knowing there is no one in the left lane who will want to exit ). The inside or left lane is to be used when you are going around more than one exit. If you use the outside / right lane to go around more than one exit when there are cars in the inside lane that will need to exit > this is wrong and shouldn't be done. Even worst not allowing the inside lane to make that turn will stop traffic on the outside lane and create a dangerous situation.
These points are shown at the following link
http://www.abnaengineering.com/abna/sld006.htm
The slide does show a case were two lane of traffic enter into a circle and the outside lane is going 2 exits but that car on the outside lane must exit into the right lane to allow the car on the inside to exit into the left exit lane.
As always drive defensively, with caution, and use your blinker especially in roundabouts.