[Mirroring] MX ComboBox selection is weird when using layoutDirection of rtl and NOT using MXFTEText.css

Found in 4.5.0.14124

Steps to reproduce:
1. Compile and run attached MXML file but NOT using MXFTEText.css ("Use Flash Text Engine for MX components" is disabled).
2. Change the layoutDirection to "rtl".
3. Open teh ComboBox control.
4. Scroll to the bottom of the ComboBox and roll over each of the options in the pop up.

Actual Results:
The last two items in the ComboBox arent rollover-able.

Expected Results:
They should be. This works with "ltr" and when using MXFTEText.css.

Workaround (if any):
Enable MXFTEText.css