Linking patch objects' XData with linkprop

In version 2010a (windows), the XData of patch objects do not seem to link properly with linkprop. Here's an example:

% create 2 patches
figure
hp(1)=patch([ 0.1 0.5 0.5 0.1], [0 0 0.5 0.5], 'r'); % lower patch
hp(2)=patch([ 0.1 0.5 0.5 0.1], [0.6 0.6 1 1], 'r'); % upper patch
set(gca,'XLim',[0 1])
% link their XData
hlinkXdata = linkprop(hp, 'XData');

% Change the upper patches XData - move it to the right
set(hp(2), 'XData', [0.4 0.7 0.7 0.4])
% lower patch should move too, but it does not

Linking the FaceColor of the patches does work:

% link patches facecolor
hlinkColor=linkprop(hp, 'FaceColor');
% change one's color, the other changes too
set(hp(2),'facecolor','b')

It's not an XData issue because linking XData of line objects does work:

% create 2 lines
hL(1)=line([0.05 0.05], [0 0.5]);
hL(2)=line([0.05 0.05], [0.6 1.0]);
% link their XData
hlinkLine=linkprop(hL, 'XData')
% change one, the other changes too
set(hL(2), 'XData', [0.95 0.95])

Is there something that needs to be done differently to link the XData property of patches?