Thank you for writing.
Your sequence of actions is correct, but here is the place to explain the visualization of the appointment in Day view. The example is similar to yours, create an appointment from 10:10 to 10:20, if the range is bigger than the duration, it will be represented in the cells that contains that interval. If the range is half an hour, you will see this appointment in the cell that starts in 10:00 and it will be represented in the whole area of that cell. If the range is 10 minutes, the appointment will be represented in the whole area of the cell which start at 10:10. If the range is 6 minutes, the appointment will be represented in the whole area of the cells that contain that period - 10:06 to a cell which starts at 10:18.
I hope that you will find this information helpful. Do not hesitate to contact me in case you need further assistance.
All the best,
the Telerik team
Q3’10 SP1 of RadControls for WinForms is available for download
; also available is the Q1'11 Roadmap
for Telerik Windows Forms controls.