OK, found the problem, our check is rounding anything less than 50 cents to 0 and then it fails the test
so - there are 6 places to change on
templates/flexible_darkmart/html/com_virtuemart/category/default.php
where ever you see
number_format($product->prices, 0, ',', '.'))
change to
number_format($product->prices, 2, ',', '.'))
they will be arround lines 410, 427, 596, 603, 789, 1140
this check is also used for quick buy etc so basically if you see this problem just change all the string above from 0 to 2
Cheers