you could try adding an onClick event to the spry tabs <li> tag to reinitialize the gallery.
<li class="TabbedPanelsTab" tabindex="0" onclick="new pgGridFullsize($('pg1'))">
<div align="center">Hard Tops</div>
then in the hard tops spry container, find the power gallery div:
and add an ID:
<div class="pg-gf" id="pg1">
make sure each gallery div has a unique ID and reference it in the onClick event from Tab panel.