SummaryViews Extension Height & Width of Portlet is not Reflecting in Plugin Mode

I am using an extension (as given below) to show an portlet in plugin mode. In this extension i am using a <dialogSize> Property to increase height and width of portlet. But height & width is not reflecting in plugin mode. and appearing with it's default height and width

<extension id="com.vmware.samples.vspherewssdk.datastore.summary">

  <extendedPoint>vsphere.core.datastore.summarySectionViews.html</extendedPoint>

  <object>

  <name>#{summaryView.title}</name>

  <contentSpec>

        <url>/ui/vspherewssdk/resources/vm-summary.html</url>

        <dialogSize>440,400</dialogSize>

  </contentSpec>

  </object>

</extension>

Note: I am using V-Center Server 6.5U2.

Please provide some guidance.

Thanks in Advance

Regards

Dharmesh