I kind of see an issue but not exactly as you do. When I view the "All Time" kudo leaders on the Machine Vision board your user shows up on page one as the 21st and on page two as the 23rd (both with 24 Kudos).
What I supect is happening is that the sorting of the leaders is dynamicly generated when the page is loaded and then binned in groups of 21 (21 users displayed per page). There are a few users along with your self that have 24 all time kudos on that board. Additionally, the page only displays 21 users and this is splitting user list right in the middle of the 24kudo group. I don't know how the page sorts the users with the same number of kudos (does it go alphabetically?). What I suspect happens sometimes is sorting the 24kudo group is different between the page one rendering and page two. So for me your user shows up on both pages, but for you the list has your user on the "other" page (on page two when viewing page one, and on page one when viewing page two).
We could test this if we could change the number that the can show per page.
