I agree, you really should use the Audio Mezzanine card, it is much easier to get the wiring correct. The App Note was written before the Audio Mezzanine became available.
However if you have hand wired the headset jack, the one thing I would look out for is the Headset Switch. Depending on the jack you have selected, there are a bunch of different possible switch wirings inside the jack. Some are normally open, and some are normally closed, additionally some connect to the tip, and others connect to one of the barrel rings. Make sure the jack you selected matches the one in the app note.
Full disclosure, I am an employee of Qualcomm Canada, any opinions I may have expressed in this or any other post may not reflect the opinions of my employer.