Just an additional comment from an amateur

VM 1.1 user, who just was trying to find a solution for this, too:
I deleted the colon in line 554 which is:
$html .= "<tr><td colspan="2"><strong>".$VM_LANG->_('PHPSHOP_PRODUCT_TYPE_PARAMETERS_IN_CATEGORY'). ": ".$dbag->f("product_type_name")."</strong></td></tr>n";
and changed "Parameters of Category" in the administrator/components/com_virtuemart/languages/common/english.php (around line 567) to read "Product". With a product type labled "Details" the product type heading now displays "Product Details" instead of the "Parameters of Category" text.
Best Regards
Joerg