Reverse foreign currency transaction

I am trying to setup a button to allow me to cancel a particular transaction.

A Budget Ticket is created which tracks an employee taking money from the till to go a buy items for use in the shop.

If the items were not available the employee will need to return the money and we will cancel the transaction (Kind of like @Jesse’s abort ticket principal).

I have created the relevant actions and rules to allow an account transaction to be fired to reverse the money that was paid out to the employee.

Inside the Cash (MXN) account everything looks good…

But… on the overall accounts listing, it is as if this MXN transaction hasn’t been processed as MXN and the overal headers suggest that the accounts are not balanced…

This is a bit confusing since the details of the Cash (MXN) do seem to be correct.

The transaction type is setup as follows…

Any ideas?