I am sharing this based on a solutions that resulted from a premium support ticket:
Since the last major upgrade of WPeC the theme.functions.php file stopped supporting custom category views (grid and list) when the category was inserted via a shortcode. This broke most of my page displays. Despite several attempts to get this amended by the development team for a new release, this issue has been duly ignored (as so many other issues), even though the solution is available and surprisingly simple:
1. Go to /plugins/wp-e-commerce/wpsc-includes/theme.functions.php
2. approx. around line 988 replace
$saved_display = wpsc_get_customer_meta( 'display_type' ); $display_type = ! empty( $saved_display ) ? $saved_display : wpsc_check_display_type();
//$saved_display = wpsc_get_customer_meta( 'display_type' ); //$display_type = ! empty( $saved_display ) ? $saved_display : wpsc_check_display_type(); if ( isset( $_SESSION['wpsc_display_type'] ) ) $display_type = $_SESSION['wpsc_display_type'];
Unless the developers add this simple fix to the next release, make sure you re-edit the file after the next upgrade.