At the bottom of the my moodle page, ellipsis (...) is displayed when the user has more courses than the preference setting allows to be displayed (although it didn't really work that way). The way it really worked was this:
The number of courses used to be hard coded at 21. There courses we displayed, and if the count was >20, then the ellipsis would be displayed. I get the felling this was originally only supposed to display the first 20 courses, and the 21 was to allow a marker that there are more. But the implementation showed all the courses returned (all 21). If you have 21 courses, they will all show plus you get the ellipsis, not a correct behavior.
Now the 21 was changed to a preference setting in MDL-13224, but the ellipsis setting was never changed, so if the preference is set to 50, and 32 courses are displayed, the ellipsis will still show.
The first attached diff should show how to correct that problem, but it doesn't correct the 1 off problem I described above.
The second diff would correct both problems.
Both diffs are off of current MOODLE_19_STABLE and I HAVE NOT tested them extensively yet.