diff --git a/gui/src/aaregui/panels/reference_tools_panel.py b/gui/src/aaregui/panels/reference_tools_panel.py
index e3b5a2c3..b6865b1d 100644
--- a/gui/src/aaregui/panels/reference_tools_panel.py
+++ b/gui/src/aaregui/panels/reference_tools_panel.py
@@ -78,12 +78,14 @@ class ReferenceToolsModel(QAbstractTableModel):
 
     def update_rows(self, rows: list[SampleShortInfo]):
         self.beginResetModel()
-        self.samples = rows
-        if self.samples:  # Only sort if we have samples
-            self._sort()
-        else:
-            self.__sorted_samples = []  # Clear sorted samples if no data
-        self.endResetModel()
+        try:
+            self.samples = rows
+            if self.samples:  # Only sort if we have samples
+                self._sort()
+            else:
+                self.__sorted_samples = []  # Clear sorted samples if no data
+        finally:
+            self.endResetModel()
 
 
     def sort(self, column, order):
@@ -106,11 +108,19 @@ class ReferenceToolsModel(QAbstractTableModel):
                 key=lambda row: row.loc_str_sort(),
                 reverse=(self.__sort_order == Qt.SortOrder.DescendingOrder)
             )
-        else:
-            # Generic sorting for other columns
+        elif self.__sort_col == 2:
+            # Numeric sort for Mount count; place None last on ascending, first on descending
+            none_sentinel = float('inf') if self.__sort_order == Qt.SortOrder.AscendingOrder else float('-inf')
             self.__sorted_samples = sorted(
                 self.samples,
-                key=lambda row: get_entry(row, self.__sort_col) or "",
+                key=lambda row: (row.mount_count if isinstance(row.mount_count, (int, float)) else none_sentinel),
+                reverse=(self.__sort_order == Qt.SortOrder.DescendingOrder)
+            )
+        else:
+            # String sort with empty fallback
+            self.__sorted_samples = sorted(
+                self.samples,
+                key=lambda row: (get_entry(row, self.__sort_col) or ""),
                 reverse=(self.__sort_order == Qt.SortOrder.DescendingOrder)
             )
 
@@ -227,7 +237,7 @@ class ReferenceToolsPanel(QFrame):
         if action == act_mount:
             self.mount.emit(item, True)
         elif action == act_unmount:
-            self.unmount.emit(item)
+            self.unmount.emit()
 
     @Slot(SampleShortInfoList)
     def new_list(self, samples: SampleShortInfoList):