diff --git a/grader b/grader
--- a/grader
+++ b/grader
@@ -167,11 +167,16 @@
 
   grader_proc.report_active if grader_proc!=nil
 
-  prob = Problem.find_by_name(ARGV[2])
-  if prob==nil
-    puts "cannot find problem: #{ARGV[2]}"
-  else
-    runner.grade_problem(prob)
+  ARGV.shift
+  ARGV.shift
+
+  ARGV.each do |prob_name|
+    prob = Problem.find_by_name(prob_name)
+    if prob==nil
+      puts "cannot find problem: #{prob_name}"
+    else
+      runner.grade_problem(prob)
+    end
   end
 
 else
diff --git a/std-script/box.cc b/std-script/box.cc
--- a/std-script/box.cc
+++ b/std-script/box.cc
@@ -29,7 +29,7 @@
 #define UNUSED __attribute__((unused))
 
 static int filter_syscalls;		/* 0=off, 1=liberal, 2=totalitarian */
-static int timeout;
+static double timeout;
 static int pass_environ;
 static int use_wall_clock;
 static int file_access;
@@ -327,10 +327,10 @@
 static void
 check_timeout(void)
 {
-  int sec;
+  double sec;
 
   if (use_wall_clock)
-    sec = time(NULL) - start_time;
+    sec = (double)(time(NULL) - start_time);
   else
     {
       char buf[4096], *x;
@@ -363,12 +363,12 @@
       if (sscanf(x, "%*c %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %d %d", &utime, &stime) != 2)
 	die("proc syntax error 2");
       //printf("%s - %d\n",x,ticks_per_sec);
-      sec = (utime + stime + ticks_per_sec-1)/ticks_per_sec;
+      sec = ((double)(utime + stime))/(double)ticks_per_sec;
     }
   if (verbose > 1)
     fprintf(stderr, "[timecheck: %d seconds]\n", sec);
   if (sec > timeout) {
-    die("Time limit exceeded.");
+    die("Time limit exceeded.",sec,timeout);
   }
 }
 
@@ -466,7 +466,10 @@
 	  box_pid = 0;
 	  if (WEXITSTATUS(stat))
 	    fprintf(stderr,"Exited with error status %d.\n", WEXITSTATUS(stat));
-	  else if ((use_wall_clock ? wall : total.tv_sec) > timeout)
+	  else if ((use_wall_clock ? 
+		    wall : 
+		    (double) total.tv_sec + 
+		    ((double) total.tv_usec/1000000.0)) > timeout)
 	    fprintf(stderr,"Time limit exceeded.\n");
 	  else
 	    // report OK and statistics
@@ -646,7 +649,7 @@
 	redir_stdout = optarg;
 	break;
       case 't':
-	timeout = atol(optarg);
+	timeout = atof(optarg);
 	break;
       case 'T':
 	allow_times++;
diff --git a/test/data/ev/test_timeout/test_cases/all_tests.cfg b/test/data/ev/test_timeout/test_cases/all_tests.cfg
--- a/test/data/ev/test_timeout/test_cases/all_tests.cfg
+++ b/test/data/ev/test_timeout/test_cases/all_tests.cfg
@@ -5,12 +5,16 @@
   mem_limit_each 16
   score_each 10
 
+  test 1 do
+    time_limit 0.5
+  end
+
   run 1 do
     tests 1
   end
 
   test 2 do
-    time_limit 2
+    time_limit 0.6
   end
 
   run 2 do
diff --git a/test/data/test2_05sec.c b/test/data/test2_05sec.c
new file mode 100644
--- /dev/null
+++ b/test/data/test2_05sec.c
@@ -0,0 +1,38 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/time.h>
+#include <time.h>
+#include <sys/resource.h>
+
+// run it for 1.5 s
+
+int main()
+{
+  int a,b;
+
+  int c=0;
+
+  scanf("%d %d",&a,&b);
+  printf("%d\n",a+b);
+
+  struct rusage ru;
+
+  while(1) {
+    c++;
+    b+=c;
+    while(c<100000) {
+      c++;
+      b+=c;
+    }
+    getrusage(RUSAGE_SELF,&ru);
+    double rtime = ru.ru_utime.tv_sec + ru.ru_stime.tv_sec;
+    rtime += (double)ru.ru_utime.tv_usec / 1000000.0;
+    rtime += (double)ru.ru_stime.tv_usec / 1000000.0;
+    if(rtime > 0.5)
+      break;
+  }
+  printf("%d\n",b);
+  exit(0);
+}
+
diff --git a/test/data/test2_1-5sec.c b/test/data/test2_1-5sec.c
deleted file mode 100644
--- a/test/data/test2_1-5sec.c
+++ /dev/null
@@ -1,41 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <sys/time.h>
-#include <time.h>
-#include <sys/resource.h>
-
-int main()
-{
-  int a,b;
-
-  int c=0;
-
-  scanf("%d %d",&a,&b);
-  printf("%d\n",a+b);
-
-  struct rusage ru;
-
-  while(1) {
-    c++;
-    b+=c;
-    while(c<1000000000) {
-      c++;
-      b+=c;
-    }
-    getrusage(RUSAGE_SELF,&ru);
-    if((ru.ru_utime.tv_sec + ru.ru_stime.tv_sec)>=1)
-      break;
-  }
-  printf("%d\n",b);
-  c=0;
-  while(c<100000000) {
-    c++;
-    b+=c;
-  }
-  if(b==10)
-    printf("hello\n");
-
-  exit(0);
-}
-
diff --git a/test/engine_spec.rb b/test/engine_spec.rb
--- a/test/engine_spec.rb
+++ b/test/engine_spec.rb
@@ -48,11 +48,11 @@
                     :comment => 'FAILED: TT'})
   end
 
-  it "should produce timeout error correctly when submission runs slower than expected in less than a second" do
-    @problem_test_timeout = stub(Problem,
+  it "should produce timeout error correctly with fractional running time and fractional time limits" do
+     @problem_test_timeout = stub(Problem,
                                  :id => 1, :name => 'test_timeout', 
                                  :full_score => 20)
-    grader_should(:grade => "test2_1-5sec.c",
+    grader_should(:grade => "test2_05sec.c",
                   :on => @problem_test_timeout,
                   :and_report => {
                     :score => 10,