dripping water

every so often over the years I have noticed a small drip or so of water coming out from under the freezer. I chalked it up to the drain pan getting full and spilling over and just waited for it to evaporate. lately there has been quite a bit more than before. I pulled the freezer out, cleaned everything up, and looked for the drip pan. I was surprised to find that there was none. the water is dripping from inside the foam wrap around the copper pipe coming out of the bottom of the side of the freezer. the pipe goes around in a circle eventually ending up going in to a black pot that has the label R134a on it. I assume that this is my compressor and that it uses r134 refrigerant. so I figure it must be condensing water from the air, its building up in the foam pipe insulation and dripping on the floor. what can I do to stop this? or am I wrong and I have a problem?