How can I produce cash basis accounting reports?

OpenERP by default does all its accounting/entries on an accrual basis. For tax reasons I need to be able to produce reports on a cash basis: when the actual payment or transfer was made and not on the date of the invoice.

Is it possible to setup such reports? (The tax reports have an option by invoice or by payment but it doesn't seem to make a difference, perhaps that is just a defect there?)