Xasks! You've said this a few times now my friend in different threads and I just want to warn you to do adequate research before posting something as fact. We don't want misinformation floating around on the forums that might cause harm to others. Paracetamol, APAP (N-Acetyl-Para-Amino-Phenol) and Acetaminophen are all synonyms for the same substance and are indeed removable through Cold Water Extraction. APAP is indeed the most commonly used NSAID in combination products like Tylenol #_, Vicodin/Lortab and Percocet. It is easily removable, so don't anyone stress about it.
I am in agreement that this could just be an issue of tolerance. It really can sneak up on you. With that said though, we'd still like to know a little bit more about your technique, as an extraction like this should not be hard to pull off with a high-yield. You really shouldn't need a different extraction method, as this one works very well and is quite simple, hence, we would like to know more about what's going on.