Shop Settings:
(http://i49.photobucket.com/albums/f263/_cycosis_/salepricingnotshowing.jpg)
Product page pricing settings:
(http://i49.photobucket.com/albums/f263/_cycosis_/salesprcingproductpage.jpg)
Product page: Red circle is area where it should have the reg price striked through according to directions here on virtumart forums.
(http://i49.photobucket.com/albums/f263/_cycosis_/salespricingnostrike.jpg)
You are not using a current VM version. http://forum.virtuemart.net/index.php?topic=118683.0
You apparently display "Base price with tax" which should show a strikethrough. See http://forum.virtuemart.net/index.php?topic=121993.msg416383#msg416383
If it does not show then you will have to update your template overrides to show the current price display code.