diff --git a/core/app.py b/core/app.py
index 09926cbe..bec30f3c 100644
--- a/core/app.py
+++ b/core/app.py
@@ -21,8 +21,7 @@
 from hscommon.path import Path
 from hscommon.conflict import smart_move, smart_copy
 from hscommon.gui.progress_window import ProgressWindow
-from hscommon.util import (delete_if_empty, first, escape, nonone, format_time_decimal, allsame,
-    rem_file_ext)
+from hscommon.util import delete_if_empty, first, escape, nonone, format_time_decimal, allsame
 from hscommon.trans import tr
 from hscommon.plat import ISWINDOWS
 from hscommon import desktop
@@ -90,10 +89,7 @@ def format_dupe_count(c):
     return str(c) if c else '---'
 
 def cmp_value(dupe, attrname):
-    if attrname == 'name':
-        value = rem_file_ext(dupe.name)
-    else:
-        value = getattr(dupe, attrname, '')
+    value = getattr(dupe, attrname, '')
     return value.lower() if isinstance(value, str) else value
 
 def fix_surrogate_encoding(s, encoding='utf-8'):
@@ -205,13 +201,11 @@ def _get_dupe_sort_key(self, dupe, get_group, key, delta):
         else:
             result = cmp_value(dupe, key)
         if delta:
-            refval = getattr(get_group().ref, key)
+            refval = cmp_value(get_group().ref, key)
             if key in self.result_table.DELTA_COLUMNS:
                 result -= refval
             else:
-                # We use directly getattr() because cmp_value() does thing that we don't want to do
-                # when we want to determine whether two values are exactly the same.
-                same = getattr(dupe, key) == refval
+                same = cmp_value(dupe, key) == refval
                 result = (same, result)
         return result
     
diff --git a/core/gui/result_table.py b/core/gui/result_table.py
index a9862f71..155db06f 100644
--- a/core/gui/result_table.py
+++ b/core/gui/result_table.py
@@ -42,7 +42,7 @@ def is_cell_delta(self, column_name):
             dupe_info = self.data
             ref_info = self._group.ref.get_display_info(group=self._group, delta=False)
             for key, value in dupe_info.items():
-                if ref_info[key] != value:
+                if (key not in self._delta_columns) and (ref_info[key].lower() != value.lower()):
                     self._delta_columns.add(key)
         return column_name in self._delta_columns
     
diff --git a/core/tests/result_table_test.py b/core/tests/result_table_test.py
index 9640a433..82b0636a 100644
--- a/core/tests/result_table_test.py
+++ b/core/tests/result_table_test.py
@@ -44,3 +44,13 @@ def test_delta_flags_delta_mode_on_non_delta_columns():
     assert not app.rtable[3].is_cell_delta('name')
     # "ibabtu" == "ibabtu", flag off
     assert not app.rtable[4].is_cell_delta('name')
+
+def test_delta_flags_delta_mode_on_non_delta_columns_case_insensitive():
+    # Comparison that occurs for non-numeric columns to check whether they're delta is case
+    # insensitive
+    app = app_with_results()
+    app.app.results.groups[1].ref.name = "ibAbtu"
+    app.app.results.groups[1].dupes[0].name = "IBaBTU"
+    app.rtable.delta_values = True
+    # "ibAbtu" == "IBaBTU", flag off
+    assert not app.rtable[4].is_cell_delta('name')
diff --git a/core/tests/results_test.py b/core/tests/results_test.py
index bade68c1..e6803564 100644
--- a/core/tests/results_test.py
+++ b/core/tests/results_test.py
@@ -230,6 +230,23 @@ def test_group_of_duplicate_after_removal(self):
         # also remove group ref
         assert self.results.get_group_of_duplicate(ref) is None
     
+    def test_dupe_list_sort_delta_values_nonnumeric(self):
+        # When sorting dupes in delta mode on a non-numeric column, our first sort criteria is if
+        # the string is the same as its ref.
+        g1r, g1d1, g1d2, g2r, g2d1 = self.objects
+        # "aaa" makes our dupe go first in alphabetical order, but since we have the same value as
+        # ref, we're going last.
+        g2r.name = g2d1.name = "aaa"
+        self.results.sort_dupes('name', delta=True)
+        eq_("aaa", self.results.dupes[2].name)
+    
+    def test_dupe_list_sort_delta_values_nonnumeric_case_insensitive(self):
+        # Non-numeric delta sorting comparison is case insensitive
+        g1r, g1d1, g1d2, g2r, g2d1 = self.objects
+        g2r.name = "AaA"
+        g2d1.name = "aAa"
+        self.results.sort_dupes('name', delta=True)
+        eq_("aAa", self.results.dupes[2].name)
 
 class TestCaseResultsWithSavedResults:
     def setup_method(self, method):