A4 in FF

My daughter's '00 1.8t Beetle was purchased with about 10k on a timing belt replacement. After about 17k on the replacement she started losing coolant erratically, then in the end very rapidly. It was dripping out from behind the lower pulley on the crankshaft, so I figured it was water pump. I replaced it with a Gates metal impeller pump and it was fine for about 2 weeks. Now I discovered a puddle under it again. I just looked and again it is leaking out from beneath the lower pulley. The first pump I pulled was, almost certainly, installed when the timing belt was done. What am I missing? Is this just plain dumb luck? Is there another reason that it would leak down the front of the engine? I'm so sick of fixing cars right now.