diff --git a/src/c64formats.c b/src/c64formats.c
index 027b63ca..00a3098e 100644
--- a/src/c64formats.c
+++ b/src/c64formats.c
@@ -105,6 +105,8 @@ void Test_C64(T_IO_Context * context, FILE * file)
       if (!Read_word_le(file, &load_addr))
         return;
   }
+  if (load_addr < 0x0400) // No PRG could load to Zeropage or processor stack
+    return;
   GFX2_Log(GFX2_DEBUG, "Test_C64() file_size=%ld LoadAddr=$%04X\n", file_size, load_addr);
   if (!Read_bytes(file, header, sizeof(header)))
     return;
diff --git a/src/stformats.c b/src/stformats.c
index ba06e719..38adc161 100644
--- a/src/stformats.c
+++ b/src/stformats.c
@@ -1797,7 +1797,7 @@ void Save_CA1(T_IO_Context * context)
               }
               else
               {
-                GFX2_Log(GFX2_DEBUG, "byte %02X x %hu\n", current, count);
+                //GFX2_Log(GFX2_DEBUG, "byte %02X x %hu\n", current, count);
                 if (count < 256)
                 {
                   // ESC,a,b => repeat (a + 1) x byte b