diff --git a/tests/test_tiling.py b/tests/test_tiling.py
index af40ced..89e38fc 100644
--- a/tests/test_tiling.py
+++ b/tests/test_tiling.py
@@ -26,7 +26,7 @@ def test_equispaced_use_full_reference_as_region():
 
     assert actual[0][0] == 1
     assert actual[0][1] == 201
-    assert actual[-1][0] == 2748 #2949 #2748 (old number where last windows where excluded)
+    assert actual[-1][0] == 2949 #2748 (old number where last windows where excluded)
     #assert actual[-1][0] + 201 < 3000
 
 
diff --git a/viloca/b2w.py b/viloca/b2w.py
index d3953b2..d3f4e40 100644
--- a/viloca/b2w.py
+++ b/viloca/b2w.py
@@ -157,6 +157,7 @@ def _run_one_window(samfile, window_start, reference_name, window_length,control
     # TODO: window_length
     original_window_length = window_length
     window_length = control_window_length
+    original_minimum_overlap = minimum_overlap
     if extended_window_mode:
         # this is now done intilaly for all windows
         #for pos, val in max_ins_at_pos.items():
@@ -208,7 +209,8 @@ def _run_one_window(samfile, window_start, reference_name, window_length,control
 
 
         if (first_aligned_pos + minimum_overlap < window_start + 1 + window_length
-                and last_aligned_pos >= window_start + minimum_overlap - 2 # TODO justify 2
+                and last_aligned_pos >= window_start + original_minimum_overlap - 2 # TODO justify 2
+                #last_aligned_pos: is in the orginal reference genome space (not in the extended_window_mode-space)
                 and len(full_read) >= minimum_overlap):
 
             num_inserts_right_of_read = 0
@@ -684,30 +686,6 @@ def parallel_run_one_window(
 
 
 
-def update_tiling(tiling, extended_window_mode, max_ins_at_pos):
-    """
-    input tiling:
-
-    return: tiling = [
-            (window_start, original_window_length, control_window_length, counter)
-            for each window
-            ]
-    """
-    update_tiling = []
-
-    for idx, (window_start, window_length) in enumerate(tiling):
-        original_window_length = window_length
-        if extended_window_mode:
-            for pos, val in max_ins_at_pos.items():
-                if window_start <= pos < window_start + original_window_length:
-                    window_length += val
-            update_tiling.append((window_start,original_window_length, window_length))
-        else:
-            update_tiling.append((window_start,original_window_length, window_length))
-
-    return update_tiling
-
-
 def build_windows(alignment_file: str, tiling_strategy: TilingStrategy,
     win_min_ext: float, maximum_reads: int, minimum_reads: int,
     reference_filename: str,
diff --git a/viloca/local_haplotype_inference/learn_error_params/preparation.py b/viloca/local_haplotype_inference/learn_error_params/preparation.py
index 4b82217..fe80925 100644
--- a/viloca/local_haplotype_inference/learn_error_params/preparation.py
+++ b/viloca/local_haplotype_inference/learn_error_params/preparation.py
@@ -103,5 +103,6 @@ def reference2binary(reference_seq, alphabet):
     length_seq = len(reference_seq)
     reference_table = np.zeros((length_seq, len(alphabet)))
     for base_position, base in enumerate(str(reference_seq)):
-        reference_table[base_position][alphabet.index(base.upper())] = 1
+        if alphabet.find(base) >= 0:
+            reference_table[base_position][alphabet.index(base.upper())] = 1
     return reference_table
diff --git a/viloca/local_haplotype_inference/use_quality_scores/preparation.py b/viloca/local_haplotype_inference/use_quality_scores/preparation.py
index add95ff..beab500 100644
--- a/viloca/local_haplotype_inference/use_quality_scores/preparation.py
+++ b/viloca/local_haplotype_inference/use_quality_scores/preparation.py
@@ -158,5 +158,6 @@ def reference2binary(reference_seq, alphabet):
     length_seq = len(reference_seq)
     reference_table = np.zeros((length_seq, len(alphabet)))
     for base_position, base in enumerate(str(reference_seq)):
-        reference_table[base_position][alphabet.index(base.upper())] = 1
+        if alphabet.find(base) >= 0:
+            reference_table[base_position][alphabet.index(base.upper())] = 1
     return reference_table
diff --git a/viloca/tiling.py b/viloca/tiling.py
index 30fd56f..2665f2b 100644
--- a/viloca/tiling.py
+++ b/viloca/tiling.py
@@ -103,9 +103,8 @@ def get_window_tilings(self) -> List[Tuple[int, int]]:
                 self.end - 1,
                 self.incr
             ))
-            while window_positions[-1] + self.window_length >= self.end:
-                del window_positions[-1] # FIXME uncommented to create one single window
-                #window_positions.append(self.end - 1 - self.window_length)
+            #while window_positions[-1] + self.window_length >= self.end:
+            #    del window_positions[-1] # FIXME uncommented to create one single window
 
         else:
             window_positions = list(range(