diff --git a/ArcFormats/ArcPACKDAT.cs b/ArcFormats/ArcPACKDAT.cs
index f9feddfe..d89b264e 100644
--- a/ArcFormats/ArcPACKDAT.cs
+++ b/ArcFormats/ArcPACKDAT.cs
@@ -80,11 +80,12 @@ namespace GameRes.Formats.SystemEpsylon
         public override Stream OpenEntry (ArcFile arc, Entry entry)
         {
             var pentry = entry as PackDatEntry;
-            if (null == pentry || entry.Size < 4 || 0 == (pentry.Flags & 0x10000))
+            if (null == pentry || entry.Size < 4
+                || !(0 != (pentry.Flags & 0x10000) || entry.Name.HasExtension (".s")))
                 return arc.File.CreateStream (entry.Offset, entry.Size);
 
             var input = arc.File.View.ReadBytes (entry.Offset, pentry.Size);
-            if (input.Length == pentry.Size)
+            if (0 != (pentry.Flags & 0x10000))
             {
                 unsafe
                 {
@@ -92,7 +93,7 @@ namespace GameRes.Formats.SystemEpsylon
                     {
                         uint* encoded = (uint*)buf_raw;
                         uint key = pentry.Size >> 2;
-                        key = (key << (((int)key & 7) + 8)) ^ key;
+                        key ^= key << (((int)key & 7) + 8);
                         for (uint i = entry.Size / 4; i != 0; --i )
                         {
                             *encoded ^= key;
@@ -102,6 +103,11 @@ namespace GameRes.Formats.SystemEpsylon
                     }
                 }
             }
+            if (entry.Name.HasExtension (".s"))
+            {
+                for (int i = 0; i < input.Length; ++i)
+                    input[i] ^= 0xFF;
+            }
             return new BinMemoryStream (input, entry.Name);
         }
     }