diff -ru ../scidcvs.git/Info.plist ./Info.plist
--- ../scidcvs.git/Info.plist	2009-04-15 11:40:07.000000000 -0500
+++ ./Info.plist	2009-07-16 02:46:26.000000000 -0500
@@ -9,6 +9,7 @@
 		<dict>
 			<key>CFBundleTypeExtensions</key>
 			<array>
+				<string>si4</string>
 				<string>si3</string>
 				<string>si</string>
 			</array>
@@ -28,6 +29,7 @@
 		<dict>
 			<key>CFBundleTypeExtensions</key>
 			<array>
+				<string>sg4</string>
 				<string>sg3</string>
 				<string>sg</string>
 			</array>
@@ -47,6 +49,7 @@
 		<dict>
 			<key>CFBundleTypeExtensions</key>
 			<array>
+				<string>sn4</string>
 				<string>sn3</string>
 				<string>sn</string>
 			</array>
diff -ru ../scidcvs.git/tcl/start.tcl ./tcl/start.tcl
--- ../scidcvs.git/tcl/start.tcl	2009-07-15 11:40:16.000000000 -0500
+++ ./tcl/start.tcl	2009-07-16 03:40:03.000000000 -0500
@@ -1036,6 +1036,13 @@
         }
         continue
       }
+      # Scid doesn't handle well .sg4 and .sn4 files.
+      if {([file extension $file] == ".sg4") || \
+            ([file extension $file] == ".sn4")} {
+        set eName ".si4"
+        set fName [file rootname $file]
+        set file "$fName$eName"
+      }
       # Scid doesn't handle well .sg3 and .sn3 files.
       if {([file extension $file] == ".sg3") || \
             ([file extension $file] == ".sn3")} {