vT 7.1 - Custom currency field database structure is broken

Working with GBP as default currency Create a custom field of type 'Currency' and set the length as 2.

edit a record with that field and enter a currency value of 2 digits e.g '£12' and it gets saved as '£1'. The database structure for this new field is decimal (8,8) - this makes no sense - as when it saves the value it is saving with 8 decimal places (it actually saves 0.99999999 which gets rounded up to 1 when displaying).

The column should be at least decimal(10,8) in order to be able to save the data required. Not sure how a length of 2 works out as being decimal(8,8) ????