Difference in visualization for area & line chart for same data provider

Steps to reproduce:
1.Copy SampleAreaChart.mxml & dp.xml
2.Run the application
3.See the difference between line and chart visulization

Actual Results:

both visualization is not same. its misleading

Expected Results:

both visulization should be same. just that in area chart, area beneath the line is filled.

Workaround (if any):
i am still looking for a work around. if you have please let me know