Hi,
1. No matter what font I use, it always happens. Any number of items can be displays and the issue still occurs. It does happen all the time. I've included screenshots.
This is what's displayed when the current item isn't indicated.
Here is what happens when I tick the box indicating the current task (although there is no current task in this particular shot). As you can see the gap (highlighted in red) appears between appointments and the task that was displayed earlier disappears (also highlighted in red).
Disappointing that you can't recreate it. Must be something wrong here. Hope you can help.
2. You can disregard the "Highlight today's appointments" issue. Your very latest version seems to have sorted that out.