Auto assignment doesn't search the memo field of split transactions, so doesn't work

- HomeBank version: 4.5.4
- Operating System: Windows XP SP3
- steps to reproduce the problem
1.-Create an Auto Assignment, Menu Manage>Assignment, for example "Aguacate" and Category="Despensa:Verduras"
2.-Add a transaction, press the split transaction button.
3.-Write in the memo field="Aguacate",
4.-Add another element on the split transaction. Press the button sum.
5.-Press the button Add,
6.-Execute the "Auto Assignments".
7-The result is that "No transaction was modified".

When we do the same procedure but with a simple transaction the process works great.