diff --git a/ps/display.c b/ps/display.c
index 11c3a832..75c7d926 100644
--- a/ps/display.c
+++ b/ps/display.c
@@ -592,7 +592,7 @@ static void finalize_stacks (void)
   // now accommodate any results not yet satisfied
   f_node = format_list;
   while (f_node) {
-    (*f_node->pr)(NULL, NULL);
+    if (*f_node->pr) (*f_node->pr)(NULL, NULL);
     f_node = f_node->next;
   }
   s_node = sort_list;
diff --git a/ps/sortformat.c b/ps/sortformat.c
index 2293aa95..965219c2 100644
--- a/ps/sortformat.c
+++ b/ps/sortformat.c
@@ -132,17 +132,20 @@ static const char *aix_format_parse(sf_node *sfn){
     c = *walk++;
     if(c=='%')    goto get_desc;
     if(!c)        goto looks_ok;
+    if(c==',')    goto aix_oops;
   /* get_text: */
     items++;
-  get_more_text:
+  get_more:
     c = *walk++;
     if(c=='%')    goto get_desc;
-    if(c)         goto get_more_text;
+    if(c==' ')    goto get_more;
+    if(c)         goto aix_oops;
     goto looks_ok;
   get_desc:
     items++;
     c = *walk++;
     if(c)         goto initial;
+  aix_oops:
     return _("improper AIX field descriptor");
   looks_ok:
     ;
@@ -313,8 +316,7 @@ static const char *format_parse(sf_node *sfn){
   if(0) improper: err=_("improper format list");
   if(0) badwidth: err=_("column widths must be unsigned decimal numbers");
   if(0) notmacro: err=_("can not set width for a macro (multi-column) format specifier");
-  if (!err)
-    if(strchr(sfn->sf,'%')) err = aix_format_parse(sfn);
+  if(strchr(sfn->sf,'%')) err = aix_format_parse(sfn);
   return err;
 }