Load balancing doesn't really work the way it sounds. If you have two 1.5Mbps internet connections you wont necessarily get 3Mbps download speeds. It will just allow two people to get 1.5Mbps download speeds at the same time or have two different downloads go at 1.5Mbps speeds.
Are you sure RG-2240 is the model of that router? I cant find anything online about it. If it is so unknown that not even google can find it your problem is probably that it is a piece of junk, lol.