[Blue07CivicEX]

might have gotten a hair of solder across the pins or just bad buttons, if you really felt ambitious you could de-solder and re-solder one, if that didn't work you could try de-soldering a broken one and the working one and swapping them to see the result, BUT then you run the risk of breaking the third one :-). If your solder job is messy you can pick up solder wick and clean some off, you can also heat up your soldering pen (I hope it's a small tip) clean the tip and draw a line between the solder points this should break any faint connection that might be bridging.