A strange problem apeared for me when I use swMenuPro to show the Virtuemart products or categories. The problem is that when I click to an link from the menu I go to the category (or product), but the Itemid stays the same as from the previus page, but I needed to change the Itemid or the Virtuemart page.
To do this go to yoursite.com/modules/mod_swmenupro/functions.php and around line 237 and 253 there should be the link (on two places):
$url="index.php?option=com_virtuemart&page=shop.product_details&flypage=shop.flypage&product_id=".$result4->product_id."&category_id=" . $result4->category_id . "&manufacturer_id=".$result4->vendor_id."&Itemid=".($Itemid)."&swid=".($result4->product_id+100000);
So just remove the Itemid or put your value.