after trying to get wpec wp ecommerce cart widget to work with super cache plugin for hours. here is what i learned.
you have to call the cart widget with shortcode, not use the widget to display the cart.
i had to edit the sidebar php to add the cart widget.
then the dynamic content tags will be recognized
<!--dynamic-cached-content--> needs to be added at the top of the widget php
<!--/dynamic-cached-content--> needs added at the bottom of the widget php
since you have to call the widget to be displayed with the short code:
<?php echo wpsc_shopping_cart(); ?>
this messed up the site navigation i used to have in the widgets settings page. so i had to convert the navigation to html and paste my site navigation plus the widget shortcode at the bottom:
<div id="sidebar2" <?php graphene_grid( 'sidebar', 1, 5, 4 ); ?>>
<div id="nav_menu-3" class="sidebar-wrap clearfix widget_nav_menu">
<li id="menu-item-63782">Contact Us
<li id="menu-item-63784">Custom Decal Request
<li id="menu-item-63791">A1 News
<?php echo wpsc_shopping_cart(); ?></div>
this displays my site navigation, then the shopping cart, (who is not cashed due to the tags i put at the top and bottom of the cart widget code) then all the other widgets are displayed below the cart via the widgets settings page.
if any of this sounds like too much code to change, you are probably going to have to go with w3tc instead. i hope this helps someone