Milestones with actual dates for baseline

I'm comparing this months progress and last months progress. I used last month's programme as a baseline for this month's programme and reflect it in the Gantt Chart. So since I'm using last month's programme as a baseline (just for comparison) there are actual dates for tasks and milestones. No problem with task dependent activities, the problem is with the milestones with actual dates. Instead of showing it behind the data date line, it was shown ahead of the data date line just like a planned date. Anyone knows how to solve this. Thanks.