Hi,
I am sorry but, what is this page? Disable the SEF URL re_writing and let me see the true URL.
in order to have our VM Template to be applied, the URL should be something like:
...../index.php?option=com_virtuemart..........
option=com_virtuemart means, that page is Virtuemart-related page. If it is something else, then it means, it is a different component and our VM template won't have any effect in there. VM Template is only affective in Virtuemart Related pages and layouts.
Cheers.