diff --git a/fsl/data/featresults.py b/fsl/data/featresults.py
index 00fb3c722083d4b0c998f7ff7d0e98cad2114f48..0bc37680aceb59fd90b89855dc17dabad0136668 100644
--- a/fsl/data/featresults.py
+++ b/fsl/data/featresults.py
@@ -385,12 +385,12 @@ def loadClusterResults(featdir, settings, contrast):
         'Z-MAX X (vox)'    : ('zmaxx',    int), 
         'Z-MAX Y (vox)'    : ('zmaxy',    int), 
         'Z-MAX Z (vox)'    : ('zmaxz',    int), 
-        'Z-COG X (vox)'    : ('zcogx',    float), 
-        'Z-COG Y (vox)'    : ('zcogy',    float), 
-        'Z-COG Z (vox)'    : ('zcogz',    float),
-        'Z-MAX X (mm)'     : ('zmaxx',    int), 
-        'Z-MAX Y (mm)'     : ('zmaxy',    int), 
-        'Z-MAX Z (mm)'     : ('zmaxz',    int), 
+        'Z-COG X (vox)'    : ('zcogx',    int), 
+        'Z-COG Y (vox)'    : ('zcogy',    int), 
+        'Z-COG Z (vox)'    : ('zcogz',    int),
+        'Z-MAX X (mm)'     : ('zmaxx',    float), 
+        'Z-MAX Y (mm)'     : ('zmaxy',    float), 
+        'Z-MAX Z (mm)'     : ('zmaxz',    float), 
         'Z-COG X (mm)'     : ('zcogx',    float), 
         'Z-COG Y (mm)'     : ('zcogy',    float), 
         'Z-COG Z (mm)'     : ('zcogz',    float), 
@@ -398,9 +398,9 @@ def loadClusterResults(featdir, settings, contrast):
         'COPE-MAX X (vox)' : ('copemaxx', int), 
         'COPE-MAX Y (vox)' : ('copemaxy', int), 
         'COPE-MAX Z (vox)' : ('copemaxz', int),
-        'COPE-MAX X (mm)'  : ('copemaxx', int), 
-        'COPE-MAX Y (mm)'  : ('copemaxy', int), 
-        'COPE-MAX Z (mm)'  : ('copemaxz', int), 
+        'COPE-MAX X (mm)'  : ('copemaxx', float),
+        'COPE-MAX Y (mm)'  : ('copemaxy', float),
+        'COPE-MAX Z (mm)'  : ('copemaxz', float),
         'COPE-MEAN'        : ('copemean', float)}
 
     # An error will be raised if the
diff --git a/fsl/fsleyes/controls/clusterpanel.py b/fsl/fsleyes/controls/clusterpanel.py
index 02f8d8b15b9a2fc40aa0d499925c2153f0e1faec..4dd03d2f1a1fc34eae1b4cc5a3e21d3c1f64c922 100644
--- a/fsl/fsleyes/controls/clusterpanel.py
+++ b/fsl/fsleyes/controls/clusterpanel.py
@@ -477,6 +477,12 @@ class ClusterPanel(fslpanel.FSLEyesPanel):
         featImage = self.__featImages[overlay]
         contrast  = self.__statSelect.GetSelection()
 
+        # No cluster results
+        if contrast < 0:
+            self.__addZStats   .Enable(False)
+            self.__addClustMask.Enable(False)
+            return
+
         zstat     = featImage.getZStats(     contrast)
         clustMask = featImage.getClusterMask(contrast)
 
diff --git a/fsl/fsleyes/gl/__init__.py b/fsl/fsleyes/gl/__init__.py
index 323da23af96ea14492f139330a2bbffaf5520145..85a7cf5d338e50afc37d756436ed2a2430fb323c 100644
--- a/fsl/fsleyes/gl/__init__.py
+++ b/fsl/fsleyes/gl/__init__.py
@@ -354,6 +354,10 @@ def bootstrap(glVersion=None):
         import fsl.fsleyes.displaycontext.display as fsldisplay
         dc.VolumeOpts   .interpolation.removeChoice('spline')
         dc.RGBVectorOpts.interpolation.removeChoice('spline')
+        dc.VolumeOpts   .interpolation.updateChoice('linear',
+                                                    newAlt=['spline'])
+        dc.RGBVectorOpts.interpolation.updateChoice('linear',
+                                                    newAlt=['spline']) 
 
         # Tensor overlays are not available in GL14
         dc        .ALL_OVERLAY_TYPES               .remove('tensor')
@@ -376,20 +380,8 @@ def bootstrap(glVersion=None):
                   'lowering default performance settings.')
 
         import fsl.fsleyes.displaycontext as dc
-
         dc.SceneOpts.performance.setConstraint(None, 'default', 2)
 
-        # And disable some fancy options - spline
-        # may have been disabled above, so absorb
-        # the ValueError if it occurs
-
-        # TODO Remove this code duplication
-        try:
-            dc.VolumeOpts   .interpolation.removeChoice('spline')
-            dc.RGBVectorOpts.interpolation.removeChoice('spline')
-            
-        except ValueError: pass
-
     thismod.GL_VERSION         = verstr
     thismod.GL_RENDERER        = renderer
     thismod.glvolume_funcs     = glpkg.glvolume_funcs