Bug 210635 Incorrect preview of chart after reverse categories.
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/computation/withaxes/PlotWith2DAxes.java
if ( dY1 < dBlockStart )
					{
						final double dDelta = ( dBlockStart - dY1 );
						dY1 = dBlockStart;
						dY += dDelta;
						dY2 += dDelta;
					}
					dBlockStart += ( dY2 - dY1 ); 
				}
				else if ( iv.getType( ) == IntersectionValue.MIN )
				
				{
					
					dY = dBlockStart + dBlockLength;
					dY += dAppliedXAxisPlotSpacing;
					dY1 = dY;
					dY2 = dY;
					if ( bTicksBelow )
					{
						dY2 += TICK_SIZE;
					}
					if ( oaxOverlay.getLabelPosition( ) == BELOW )
					{
						dY2 += Math.max( dAxisLabelsThickness,
								dDecorationThickness[1] );
						dY1 -= Math.max( bTicksAbove ? TICK_SIZE : 0,
								dAppliedXAxisPlotSpacing );
					}
					else if ( oaxOverlay.getLabelPosition( ) == ABOVE )