I had the same problem on two of mine. The first one, I thought, was because I had some soap leftover somehow from cleaning. So, on the second I rinsed and rinsed. Had the soapy flavor again! Come to find out it was because of the high temp of my fermentation (about 76). Started doing the water bath/wet shirt/fan trick. Since then, no soap.
Oh, and BTW, the flavor KIND OF subsides over time. Still there, just not as prevalent.