a few of us, myself included, have really wrestled with this off-flavor. I have dumped 5-6 batches due to this. Unfortunately, it doesn't go away with aging, but seems to get worse.
It does come down to one of two things: either some or all of the water you're using has chlorines or chloramines (which are even harder deal with - this is what I have in my water), or you have an infection on some peice of equipment.
I never figured out conclusively what was causing the problem for me, but my best guess is that, even though I was using bottled water from the store, I would make starters with tap-water or add small amounts of tap water to top-off, thinking small amounts would be ok. I was mixing my star-san with water from my basement utility sink and not placing sanitized bottles upside-down to drain properly before bottling, so there was always a little pool of the stuff at the bottom of each bottle. I think it was likely this seemingly minimal contact with my tap water that was ruining batches on a variable scale, depending on how much contact each batch had....(some were undrinkable, others just had a slight taste of bandaid in the aroma - or the burp).
My solution was to start treating all brewing water with Campden tabs, and to mix up my sanitizer with distilled water, with the added benefit that it can be reused as long as it stays clean.
Just to be safe, though, and because after 6 batches or so of this I was determined not to waste any more freakin' beer, I tossed all but the newest of my fermentors, my bottling set-up and hoses, and replaced all this stuff. I decided to do this in part because I had used the buckets for a variety of soaking and cleaning operations and scratched them all up pretty bad before I realized that scratches can harbor bacteria....even if they weren't the culprit this time, they could easily have started causing me problems....
basically, I gave myself a new process and a fresh start, and things have been great ever since. I know this doesn't solve your problem, but hopefully it will give you things to consider/think about. good luck.