=== modified file 'mrp/mrp.py'
--- mrp/mrp.py	2010-03-08 17:57:25 +0000
+++ mrp/mrp.py	2010-03-09 22:34:45 +0000
@@ -1190,6 +1190,9 @@
             help="The procurement quantity will by rounded up to this multiple."),
         'procurement_id': fields.many2one('mrp.procurement', 'Purchase Order', ondelete="set null")
     }
+    _sql_constraints = [
+        ( 'qty_multiple_check', 'CHECK( qty_multiple > 0 )', 'Qty Multiple must be greater than zero.' )
+    ]
     _defaults = {
         'active': lambda *a: 1,
         'logic': lambda *a: 'max',