OLAP mode - The "List index out of bounds" exception when expanding a grouping value of an inner column/row field after an outer field has been hidden in the same area

Here's the steps to reproduce the bug mentioned on the subject:
- PivotGrid in OLAP mode connection (.CUB file in the attachment);
- drag in a measure (Imponibile) and 3 attributes on the row-area (fig.1);
- change the order of the row fields (fig. 2);
- drag out the first attribute on the rows (fig. 3);
- expanding the values of the attribute triggers the "List index out of bounds" exception (fig. 4);

Technically speaking, I suspect the bug is due to the incorrectly setting of the "AreaIndex" property of the remaining fields placed on the PVG, when another field is dragged out.

Debugging the DevX pkgs, I've found that the exception is thrown in the function "GetNonExpandedFields" of the "cxPivotGridOLAPDataSource.pas". More precisely in the line:

Result.Add(ADataBuilder.GetFieldsListByArea(AnExpandingItem.Field.Area).Fields[AnExpandingItem.Field.AreaIndex + 1]);

In the example attached (fig.3), the field "Tipo" should have AreaIndex=0 but instead it returns 1.

Hope the explanation is clear.