Find this around line 470 of checkout.aspx.vb (root):
If numMinOrderValue > 0 Then
If GetKartConfig("general.tax.pricesinctax") = "y" Then
'Prices include tax
If UC_BasketView.GetBasket.TotalIncTax < numMinOrderValue Then
Response.Redirect("~/Basket.aspx?error=minimum")
End If
Else
If UC_BasketView.GetBasket.TotalExTax < numMinOrderValue Then
Response.Redirect("~/Basket.aspx?error=minimum")
End If
End If
End If
change to
If numMinOrderValue > 0 Then
If GetKartConfig("general.tax.pricesinctax") = "y" Then
'Prices include tax
If UC_BasketView.GetBasket.TotalIncTax < CurrenciesBLL.ConvertCurrency(Session("CUR_ID"), numMinOrderValue) Then
Response.Redirect("~/Basket.aspx?error=minimum")
End If
Else
If UC_BasketView.GetBasket.TotalExTax < CurrenciesBLL.ConvertCurrency(Session("CUR_ID"), numMinOrderValue) Then
Response.Redirect("~/Basket.aspx?error=minimum")
End If
End If
End If
This applies the present currency to the minorderval setting, so changing currency should see the min order value increased by the same amount in numeric terms as the order total