Audio problem: When your Pokemon is low on health it makes a beeping noise. This noise can interfere with Pokemon cries and attack noises (i.e. Kadabra's cry sounds like Ghastly's cry).
Bug: After entering the Cycling Road from the northern gate, go all the way left. You'll see some trees beside the barrier. Then go south, until a point water appears below the trees. If you go up again, you'll see that the trees that were at north have now transformed into water. If you keep going up, and then right so the water is not seen, and then left again, the water has now transformed into trees, again.