--- procps-3.2.8/top.c
+++ procps-3.2.8/top.c	2011-12-20 10:49:54.000000000 +0000
@@ -1147,6 +1147,11 @@ static proc_t **procs_refresh (proc_t **
    else
       PT = openproc(flags);
 
+   if (PT==NULL) {
+      std_err(strerror(errno));
+      exit(1);
+   }
+
    // i) Allocated Chunks:  *Existing* table;  refresh + reuse
    if (!(CHKw(Curwin, Show_THREADS))) {
       while (curmax < savmax) {