I tracked down a problem introduced by the behavior of TcxScheduler.OnInitEventImages.
Our problem lies in the fact that the EventImages of the scheduler is a TImageList global to our application.
If in the OnInitEventImages, an image is added to the list, the process will change the DrawingStyle of the imagelist, but won't restore the previous state once it is done. (TcxSchedulerEventCellViewInfo.DrawImages)
Would it be possible for you to restore the previous DrawingStyle once you're done painting in future releases?
Note : A similar issue exists with TcxSchedulerPainterHelper.DrawIcon and TcxSchedulerMoreEventsButtonViewInfo.DoDraw
Steps to Reproduce:
In the sample:
Select a record in the grid. You will see there is no painting problem with the icon there. (Similar to the image labeled "Before")
Add any event to the scheduler.
Return select a record in the grid. You will see the little "glitch" we get, like a white underscore under the image. (Similar to the image labeled "After")
The "Repair" button correct the problem (It just put the imagelist back to dsNormal)