Microsoft Money does not handle these type of accounts directly (such as the Virgin One account) or other types of offset mortgage. These mortgages are typically those which allow you to combine the values of other related accounts and only pay interest on the net balance.
When Money calculates interest on a mortgage, it will not combine the sum total of two accounts and then generate an interest figure on the combined amount. It will only use the loan account value to calculate this.
You could try, as a workaround, to change the 'balloon payment' to be equal to the value of the savings you have against the mortgage, but this probably will not create an accurate figure.
With a mortgage account, the types of operations you can do in Money is limited. You can't write cheques for instance. To get around this, you could track the account as a current account, and create an estimated interest rate payment for the bills and deposits area, which is then modified each month when you know how much interest you have paid. Not ideal though, but does work.
I know Microsoft know about the wishes for this one. However, it wouldn't hurt sending another one for it.
Keywords: mortgage, offset, all-in-one, current account