diff --git a/builtin/providers/aws/resource_aws_route_table.go b/builtin/providers/aws/resource_aws_route_table.go
index edc5d2d77..12a0fffe1 100644
--- a/builtin/providers/aws/resource_aws_route_table.go
+++ b/builtin/providers/aws/resource_aws_route_table.go
@@ -145,6 +145,7 @@ func resource_aws_route_table_destroy(
 
 	// Do all the disassociations
 	for _, a := range rt.Associations {
+		log.Printf("[INFO] Disassociating association: %s", a.AssociationId)
 		if _, err := ec2conn.DisassociateRouteTable(a.AssociationId); err != nil {
 			return err
 		}
diff --git a/builtin/providers/aws/resource_aws_route_table_association.go b/builtin/providers/aws/resource_aws_route_table_association.go
index f872ddf76..828508262 100644
--- a/builtin/providers/aws/resource_aws_route_table_association.go
+++ b/builtin/providers/aws/resource_aws_route_table_association.go
@@ -55,6 +55,12 @@ func resource_aws_route_table_association_update(
 		rs.ID,
 		rs.Attributes["route_table_id"])
 	if err != nil {
+		ec2err, ok := err.(*ec2.Error)
+		if ok && ec2err.Code == "InvalidAssociationID.NotFound" {
+			// Not found, so just create a new one
+			return resource_aws_route_table_association_create(s, d, meta)
+		}
+
 		return s, err
 	}
 
diff --git a/builtin/providers/aws/resource_aws_route_table_association_test.go b/builtin/providers/aws/resource_aws_route_table_association_test.go
index 944c83ba4..52e37b07e 100644
--- a/builtin/providers/aws/resource_aws_route_table_association_test.go
+++ b/builtin/providers/aws/resource_aws_route_table_association_test.go
@@ -10,7 +10,7 @@ import (
 )
 
 func TestAccAWSRouteTableAssociation(t *testing.T) {
-	var v ec2.RouteTable
+	var v, v2 ec2.RouteTable
 
 	resource.Test(t, resource.TestCase{
 		PreCheck:     func() { testAccPreCheck(t) },
@@ -24,6 +24,14 @@ func TestAccAWSRouteTableAssociation(t *testing.T) {
 						"aws_route_table_association.foo", &v),
 				),
 			},
+
+			resource.TestStep{
+				Config: testAccRouteTableAssociationConfigChange,
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckRouteTableAssociationExists(
+						"aws_route_table_association.foo", &v2),
+				),
+			},
 		},
 	})
 }
@@ -112,3 +120,23 @@ resource "aws_route_table_association" "foo" {
 	subnet_id = "${aws_subnet.foo.id}"
 }
 `
+
+const testAccRouteTableAssociationConfigChange = `
+resource "aws_vpc" "foo" {
+	cidr_block = "10.1.0.0/16"
+}
+
+resource "aws_subnet" "foo" {
+	vpc_id = "${aws_vpc.foo.id}"
+	cidr_block = "10.1.1.0/24"
+}
+
+resource "aws_route_table" "bar" {
+	vpc_id = "${aws_vpc.foo.id}"
+}
+
+resource "aws_route_table_association" "foo" {
+	route_table_id = "${aws_route_table.bar.id}"
+	subnet_id = "${aws_subnet.foo.id}"
+}
+`
diff --git a/builtin/providers/aws/resource_aws_subnet.go b/builtin/providers/aws/resource_aws_subnet.go
index 4e0ef5597..327666814 100644
--- a/builtin/providers/aws/resource_aws_subnet.go
+++ b/builtin/providers/aws/resource_aws_subnet.go
@@ -131,6 +131,10 @@ func resource_aws_subnet_diff(
 			"cidr_block":        diff.AttrTypeCreate,
 			"vpc_id":            diff.AttrTypeCreate,
 		},
+
+		ComputedAttrs: []string{
+			"availability_zone",
+		},
 	}
 
 	return b.Diff(s, c)