diff --git a/checkin_notes b/checkin_notes
index 86c8f7a2c7..ac137035fe 100755
--- a/checkin_notes
+++ b/checkin_notes
@@ -12115,9 +12115,9 @@ David  May 5 2004
         Makefile.am,in
 
 Rom    May 5 2004
-    - Our exit stragety should be the same for Windows and Unix.  The signal
-      handler should use the same global flags as Windows for suspending
-      and resuming activities.
+    - Our exit strategy should be the same for Windows and Unix.
+        The signal handler should use the same global flags as Windows
+        for suspending and resuming activities.
 
     client/
         main.C
@@ -12138,3 +12138,19 @@ Rom    May 6 2004
         failure_result_summary_by_platform.php
         index.php
         pass_percentage_by_platform.php
+
+David  May 10 2004
+    - extend the set of signals that are treated as "external",
+        i.e. if an app exits with one of these, put it in limbo
+        rather than treating it as error:
+        SIGHUP, SIGINT, SIGQUIT, SIGKILL, SIGTERM, SiGSTOP
+        Note: some of these should in principle never happen
+        because they're caught by the API.
+        But it doesn't hurt to be safe.
+    - update_average(): avoid divides by zero
+
+    client/
+        app.C
+    lib/
+        exception.h
+        util.C
diff --git a/client/app.C b/client/app.C
index e4834f0824..335e3e6446 100644
--- a/client/app.C
+++ b/client/app.C
@@ -752,7 +752,13 @@ bool ACTIVE_TASK_SET::check_app_exited() {
 
                 // if the process was externally killed, allow it to restart.
                 //
-                if (signal==SIGKILL || signal==SIGQUIT) {
+                switch(signal) {
+                case SIGHUP:
+                case SIGINT:
+                case SIGQUIT:
+                case SIGKILL:
+                case SIGTERM:
+                case SIGSTOP:
                     atp->state = PROCESS_IN_LIMBO;
                     return true;
                 }
diff --git a/doc/create_project.php b/doc/create_project.php
index fb312c712e..94c765e2b9 100644
--- a/doc/create_project.php
+++ b/doc/create_project.php
@@ -41,6 +41,7 @@ How to develop or port an application program for use with BOINC.
 <li><a href=api.php>The BOINC API</a>
 <li><a href=graphics.php>The BOINC graphics API</a>
 <li><a href=app_dev.php>Application development</a>
+<li><a href=fortran.php>FORTRAN applications</a>
 </ul>
 
 <font size=+1><b>
diff --git a/lib/exception.h b/lib/exception.h
index a062acf012..91e9cb7edf 100644
--- a/lib/exception.h
+++ b/lib/exception.h
@@ -23,6 +23,7 @@
 #ifndef _WIN32
 #include <string>
 using namespace std;
+using std::exception;
 #endif
 
 
diff --git a/lib/util.C b/lib/util.C
index 9819b912c6..4415dbc3df 100755
--- a/lib/util.C
+++ b/lib/util.C
@@ -612,14 +612,14 @@ void update_average(
 
     if (avg_time) {
         double diff = now - avg_time;
+        if (diff==0) diff=3600;     // just in case
         double diff_days = diff/SECONDS_PER_DAY;
         double weight = exp(-diff*M_LN2/half_life);
         avg *= weight;
         avg += (1-weight)*(work/diff_days);
-    } else {
+    } else if (work) {
         double dd = (now - work_start_time)/SECONDS_PER_DAY;
         avg = work/dd;
     }
     avg_time = now;
 }
-