Index: mrsiddataset.cpp
===================================================================
--- mrsiddataset.cpp	(revision 38215)
+++ mrsiddataset.cpp	(working copy)
@@ -486,6 +486,28 @@
             eBandInterp = GCI_GrayIndex;
             break;
 
+#if defined(LTI_COLORSPACE_GRAYSCALEA)
+        case LTI_COLORSPACE_GRAYSCALEA:
+            if( nBand == 1 )
+                eBandInterp = GCI_GrayIndex;
+            else if( nBand == 2 )
+                eBandInterp = GCI_AlphaBand;
+            else
+                eBandInterp = GCI_Undefined;
+            break;
+#endif
+
+#if defined(LTI_COLORSPACE_GRAYSCALEA_PM)
+        case LTI_COLORSPACE_GRAYSCALEA_PM:
+            if( nBand == 1 )
+                eBandInterp = GCI_GrayIndex;
+            else if( nBand == 2 )
+                eBandInterp = GCI_AlphaBand;
+            else
+                eBandInterp = GCI_Undefined;
+            break;
+#endif
+
         default:
             eBandInterp = GCI_Undefined;
             break;