diff --git a/scrapy/trunk/scrapy/contrib/spidermiddleware/duplicatesfilter.py b/scrapy/trunk/scrapy/contrib/spidermiddleware/duplicatesfilter.py
index 52301374f..e6a8872ab 100644
--- a/scrapy/trunk/scrapy/contrib/spidermiddleware/duplicatesfilter.py
+++ b/scrapy/trunk/scrapy/contrib/spidermiddleware/duplicatesfilter.py
@@ -40,8 +40,7 @@ class DuplicatesFilterMiddleware(object):
 
     def process_spider_output(self, response, result, spider):
         domain = spider.domain_name
-        # FIXME there's a conflict between test_spidermiddleware_duplicatesfilter.py and test_engine.py
-        #self.filter.add(domain, response.request)
+        self.filter.add(domain, response.request)
 
         for req in result:
             if isinstance(req, Request):
diff --git a/scrapy/trunk/scrapy/link/extractors.py b/scrapy/trunk/scrapy/link/extractors.py
index 3c07e46a7..a0daa46a9 100644
--- a/scrapy/trunk/scrapy/link/extractors.py
+++ b/scrapy/trunk/scrapy/link/extractors.py
@@ -41,7 +41,7 @@ class RegexLinkExtractor(LinkExtractor):
     """
 
     def __init__(self, allow=(), deny=(), allow_domains=(), deny_domains=(), restrict_xpaths=(), 
-                 tags=('a', 'area'), attrs=('href',), canonicalize=True, unique=True):
+                 tags=('a', 'area'), attrs=('href'), canonicalize=True, unique=True):
         self.allow_res = [x if isinstance(x, _re_type) else re.compile(x) for x in allow]
         self.deny_res = [x if isinstance(x, _re_type) else re.compile(x) for x in deny]
         self.allow_domains = set(allow_domains)
diff --git a/scrapy/trunk/scrapy/tests/test_spidermiddleware_duplicatesfilter.py b/scrapy/trunk/scrapy/tests/test_spidermiddleware_duplicatesfilter.py
index faf77fbc1..0a6951294 100644
--- a/scrapy/trunk/scrapy/tests/test_spidermiddleware_duplicatesfilter.py
+++ b/scrapy/trunk/scrapy/tests/test_spidermiddleware_duplicatesfilter.py
@@ -15,16 +15,19 @@ class DuplicatesFilterMiddlewareTest(unittest.TestCase):
         mw = DuplicatesFilterMiddleware()
         mw.filter.open('scrapytest.org')
 
-        response = Response('')
+        rq = Request('http://scrapytest.org/')
+        response = Response('http://scrapytest.org/')
+        response.request = rq
         r1 = Request('http://scrapytest.org/1')
         r2 = Request('http://scrapytest.org/2')
         r3 = Request('http://scrapytest.org/2')
 
         filtered = list(mw.process_spider_output(response, [r1, r2, r3], self.spider))
 
-        assert r1 in filtered
-        assert r2 in filtered
-        assert r3 not in filtered
+        self.assertFalse(rq in filtered)
+        self.assertTrue(r1 in filtered)
+        self.assertTrue(r2 in filtered)
+        self.assertFalse(r3 in filtered)
 
         mw.filter.close('scrapytest.org')
 
@@ -35,16 +38,16 @@ class SimplePerDomainFilterTest(unittest.TestCase):
         domain = 'scrapytest.org'
         filter = SimplePerDomainFilter()
         filter.open(domain)
-        assert domain in filter
+        self.assertTrue(domain in filter)
 
         r1 = Request('http://scrapytest.org/1')
         r2 = Request('http://scrapytest.org/2')
         r3 = Request('http://scrapytest.org/2')
 
-        assert filter.add(domain, r1)
-        assert filter.add(domain, r2)
-        assert not filter.add(domain, r3)
+        self.assertTrue(filter.add(domain, r1))
+        self.assertTrue(filter.add(domain, r2))
+        self.assertFalse(filter.add(domain, r3))
 
         filter.close(domain)
-        assert domain not in filter
+        self.assertFalse(domain in filter)