Multiple-step OLE DB operation generated errors

When editing a record from a MS SQL table, all the field data including nulls is being displayed in the edit field.
The problem occurs if you want to add some data to a field eg change Mr to Mrs, the field definition is long enouth to take the extra character but because the null characters are being posted as well there is not enouth space, so you get the dreaded Multiple-step OLE DB operation generated error message
How can you strip out the null characters ?