Are comments no longer creating entries on the Recent Activity page? I used to park on that page to see if anything has happened recently on a question I asked, but while watching a particular question from that page and seeing nothing happen, I drilled into the question and found several comments. I thought it used to list comments here along with the answers and what I've commented on. Has this been removed?
My comments are showing up fine on my Recent Activity page (the page you go after clicking the envelope). I am able to see any comment replies people leave for me there.
On the Recent tab of my profile, I can see comments I make, but there are no comments that other users leave for me on my content.
check the date ranges. Try clicking on "today" or "yesterday". I believe the code tries to infer a "last time you were here" date which isn't always correct.