Actually, there's another difference. The original Newcomb problem implies that it is possible for you figure out the correct answer. With genetic Newcomb, it may be impossible for you to figure out the correct answer.

It is true that having your decision determined by your genes is similar to having your decision determined by the algorithm you are executing. However, we know that both sets of genes can happen, but if your decision is determined by the algorithm you are using, certain algorithms may be contradictory and cannot happen. (Consider an algorithm that predicts what Omega will do and acts based on that prediction.) Although now that I think of it, that's pretty much the halting problem objection anyway.