Question: I was just browsing through the EIMS list on the AMS web-page, and under post-doctorate in math, I found only 24 listings. Harvard was not on it. Just wanted to check if I am doing something wrong or is it that some univs don't or have not yet posted on EIMS?

Don't restrict the search to postdocs; for example, the BP at Harvard is not classified as a postdoc. Try clicking on all of Tenure-Track, Non Tenure-Track, Post-Doc, Research, and Short Term. You'll get a healthy list of around 200 entries, including Harvard's and instructions on how to get an application from Princeton.