diff --git a/chainsyncer/backend/file.py b/chainsyncer/backend/file.py
index 0346a73..61bcb68 100644
--- a/chainsyncer/backend/file.py
+++ b/chainsyncer/backend/file.py
@@ -156,20 +156,23 @@ class SyncerFileBackend:
 
 
     def get(self):
-        return ((self.block_height_cursor, self.tx_index_cursor), self.filter)
+        logg.debug('filter {}'.format(self.filter.hex()))
+        return ((self.block_height_cursor, self.tx_index_cursor), int.from_bytes(self.filter, 'little'))
 
 
     def set(self, block_height, tx_index):
         self.__set(block_height, tx_index, 'cursor')
 
-        cursor_path = os.path.join(self.object_data_dir, 'filter')
-        f = open(cursor_path, 'r+b')
-        f.seek(8)
-        l = len(self.filter)
-        c = 0
-        while c < l:
-            c += f.write(self.filter)
-        f.close()
+#        cursor_path = os.path.join(self.object_data_dir, 'filter')
+#        f = open(cursor_path, 'r+b')
+#        f.seek(8)
+#        l = len(self.filter)
+#        c = 0
+#        while c < l:
+#            c += f.write(self.filter[c:])
+#        f.close()
+
+        return ((self.block_height_cursor, self.tx_index_cursor), int.from_bytes(self.filter, 'little'))
 
 
     def __set(self, block_height, tx_index, category):
@@ -198,15 +201,16 @@ class SyncerFileBackend:
         o.__set(target_block_height, 0, 'target')
         o.__set(start_block_height, 0, 'offset')
 
-        return uu
+        #return uu
+        return o
 
 
     def target(self):
-        return ((self.block_height_target, self.tx_index_target), None,)
+        return (self.block_height_target, 0,)
 
 
     def start(self):
-        return ((self.block_height_offset, self.tx_index_offset), None,)
+        return ((self.block_height_offset, self.tx_index_offset), 0,)
 
 
     @staticmethod
@@ -289,3 +293,15 @@ class SyncerFileBackend:
         b = self.filter_count.to_bytes(8, byteorder='big')
         f.write(b)
         f.close()
+
+
+    def reset_filter(self):
+        self.filter = b'\x00' * len(self.filter)
+        cursor_path = os.path.join(self.object_data_dir, 'filter')
+        f = open(cursor_path, 'r+b')
+        f.seek(8)
+        l = len(self.filter)
+        c = 0
+        while c < l:
+            c += f.write(self.filter[c:])
+        f.close()
diff --git a/chainsyncer/driver.py b/chainsyncer/driver.py
index 32cae8f..93fe446 100644
--- a/chainsyncer/driver.py
+++ b/chainsyncer/driver.py
@@ -170,6 +170,7 @@ class HistorySyncer(HeadSyncer):
         if block_number == None:
             raise AttributeError('backend has no future target. Use HeadSyner instead')
         self.block_target = block_number
+        logg.debug('block target {}'.format(self.block_target))
 
 
     def get(self, conn):
diff --git a/tests/test_interrupt.py b/tests/test_interrupt.py
index 238cdc9..303ad66 100644
--- a/tests/test_interrupt.py
+++ b/tests/test_interrupt.py
@@ -2,6 +2,7 @@
 import logging
 import unittest
 import os
+import tempfile
 
 # external imports
 from chainlib.chain import ChainSpec
@@ -9,6 +10,10 @@ from chainlib.chain import ChainSpec
 # local imports
 from chainsyncer.backend.memory import MemBackend
 from chainsyncer.backend.sql import SyncerBackend
+from chainsyncer.backend.file import (
+        SyncerFileBackend,
+        data_dir_for,
+    )
 
 # test imports
 from tests.base import TestBase
@@ -61,21 +66,35 @@ class TestInterrupt(TestBase):
 
     def setUp(self):
         super(TestInterrupt, self).setUp()
-        self.filters =  [
+        
+        self.backend = None
+        self.conn = MockConn()
+        self.vectors = [
+                [4, 3, 2],
+                [6, 4, 2],
+                [6, 5, 2],
+                [6, 4, 3],
+                ]
+        
+
+    def assert_filter_interrupt(self, vector):
+    
+        logg.debug('running vector {} {}'.format(str(self.backend), vector))
+
+        z = 0
+        for v in vector:
+            z += v
+
+        syncer = TestSyncer(self.backend, vector)
+
+        filters =  [
             CountFilter('foo'),
             CountFilter('bar'),
             NaughtyCountExceptionFilter('xyzzy', croak_on=3),
             CountFilter('baz'),
             ]
-        self.backend = None
-        self.conn = MockConn()
-        
 
-    def assert_filter_interrupt(self):
-       
-        syncer = TestSyncer(self.backend, [4, 3, 2])
-
-        for fltr in self.filters:
+        for fltr in filters:
             syncer.add_filter(fltr)
 
         try:
@@ -87,19 +106,33 @@ class TestInterrupt(TestBase):
         self.assertGreater(fltr, 0)
         syncer.loop(0.1, self.conn)
 
-        for fltr in self.filters:
+        for fltr in filters:
             logg.debug('{} {}'.format(str(fltr), fltr.c))
-            self.assertEqual(fltr.c, 9)
+            self.assertEqual(fltr.c, z)
 
 
+    @unittest.skip('foo')
     def test_filter_interrupt_memory(self):
-        self.backend = MemBackend(self.chain_spec, None, target_block=4)
-        self.assert_filter_interrupt()
+        for vector in self.vectors:
+            self.backend = MemBackend(self.chain_spec, None, target_block=len(vector))
+            self.assert_filter_interrupt(vector)
 
 
+    def test_filter_interrpt_file(self):
+        for vector in self.vectors:
+            d = tempfile.mkdtemp()
+            #os.makedirs(data_dir_for(self.chain_spec, 'foo', d))
+            self.backend = SyncerFileBackend.initial(self.chain_spec, len(vector), base_dir=d) #'foo', base_dir=d)
+            self.assert_filter_interrupt(vector)
+
+
+    @unittest.skip('foo')
     def test_filter_interrupt_sql(self):
-        self.backend = SyncerBackend.initial(self.chain_spec, 4)
-        self.assert_filter_interrupt()
+        for vector in self.vectors:
+            self.backend = SyncerBackend.initial(self.chain_spec, len(vector))
+            self.assert_filter_interrupt(vector)
+
+
 
 
 if __name__ == '__main__':