diff --git a/lib/submission_helper.rb b/lib/submission_helper.rb
--- a/lib/submission_helper.rb
+++ b/lib/submission_helper.rb
@@ -55,21 +55,37 @@
       result_fname = "#{test_result_dir}/result"
       comment_fname = "#{test_result_dir}/comment"  
       if FileTest.exist?(result_fname)
-        result_file = File.open(result_fname)
-        result = result_file.readline.to_i
-        result_file.close
-        
-        comment_file = File.open(comment_fname)
-        comment = comment_file.readline.chomp
-        comment_file.close
-        
+        comment = ""
+        begin
+          result_file = File.open(result_fname)
+          result = result_file.readline.to_i
+          result_file.close
+        rescue
+          result = 0
+          comment = "error reading result file."
+        end
+          
+        begin
+          comment_file = File.open(comment_fname)
+          comment += comment_file.readline.chomp
+          comment_file.close
+        rescue
+          comment += ""
+        end
+
         return {:points => result, 
           :comment => comment, 
           :cmp_msg => cmp_msg}
       else
-        return {:points => 0,
-          :comment => 'compile error',
-          :cmp_msg => cmp_msg}
+        if FileTest.exist?("#{test_result_dir}/a.out")
+          return {:points => 0,
+            :comment => 'error during grading',
+            :cmp_msg => cmp_msg}
+        else
+          return {:points => 0,
+            :comment => 'compile error',
+            :cmp_msg => cmp_msg}
+        end
       end
     end
     
diff --git a/std-script/grade b/std-script/grade
--- a/std-script/grade
+++ b/std-script/grade
@@ -45,16 +45,17 @@
   run.tests.each do |test_num|
     result_file_name = "#{test_num}/result"
     if not File.exists?(result_file_name)
+      run_comment += "result file for test #{test_num} not found\n"
+      run_comment_short += 'x'
       log "Cannot find the file #{test_num}/result!"
-      exit(127)
+    else
+      result_file = File.new(result_file_name, "r")
+      result_file_lines = result_file.readlines
+      run_score = run_score + result_file_lines[1].to_i
+      run_comment += result_file_lines[0]
+      run_comment_short += char_comment(result_file_lines[0])
+      result_file.close
     end
-
-    result_file = File.new(result_file_name, "r")
-    result_file_lines = result_file.readlines
-    run_score = run_score + result_file_lines[1].to_i
-    run_comment += result_file_lines[0]
-    run_comment_short += char_comment(result_file_lines[0])
-    result_file.close
   end
   
   run_result_file = File.new("result-#{k}", "w")
diff --git a/std-script/judge b/std-script/judge
--- a/std-script/judge
+++ b/std-script/judge
@@ -16,6 +16,7 @@
 
 def execute(command, error_message="")
   if not system(command)
+    log "ERROR: #{error_message}"
     puts "ERROR: #{error_message}"
     exit(127)
   end
diff --git a/std-script/run b/std-script/run
--- a/std-script/run
+++ b/std-script/run
@@ -132,6 +132,7 @@
 log "Checking the output..."
 log check_command
 if not system(check_command)
+  log "Problem with check script"
   exit(127)
 end