Hi,
Yes, it might be related to VM2 Cart plugin. This plugin is necessary to show the "product pictures" inside the dropdown shopping cart module.
Open this PHP file:
plugins / system / vm2_cart / vm2_cart.php
find this line:
require(JPATH_ADMINISTRATOR . DS . 'components' . DS . 'com_virtuemart'.DS.'helpers'.DS.'image.php');
and replace it with this:
if (!class_exists( 'VmImage' )) require(JPATH_ADMINISTRATOR . DS . 'components' . DS . 'com_virtuemart'.DS.'helpers'.DS.'image.php');
regards.