Update issues

Question

Hello,
I am using VS2008 C#, attempting to use ADO.NET to update a MS Access Database.
My table is called testtable, it has 2 columns: DatePaid, AmountPaid.  DatePaid is a date field, and Amountpaid is a currency field.
When I run my command it doesn't update the record.  It doesn't error, simply nothing happens.  It works fine to create tables, delete tables, delete entries, just update won't work properly.  I'm sure I got something mixed up.
My Query at runtime is: UPDATE testtable SET DatePaid=20/08/2010, AmountPaid=900 WHERE DatePaid=18/08/2010 AND AmountPaid =250
I have tried utilizing ' ' around the values, and switching the dates/values around and it still won't update an existing record.  I'm wanting to change the DatePaid Field to 20/08/2010 and the AmountPaid to 900
I'm not sure where it's going wrong.
Any help would be appreciated.