--- loncom/xml/londefdef.pm	2010/11/01 10:52:09	1.425
+++ loncom/xml/londefdef.pm	2010/11/18 17:42:15	1.426
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Tags Default Definition Module 
 #
-# $Id: londefdef.pm,v 1.425 2010/11/01 10:52:09 foxr Exp $
+# $Id: londefdef.pm,v 1.426 2010/11/18 17:42:15 raeburn Exp $
 # 
 #
 # Copyright Michigan State University Board of Trustees
@@ -2314,14 +2314,20 @@ sub tag_check {
 
 sub cell_config_hash {
     my ($align, $rowspan, $colspan, $width) = @_;
+    if ($rowspan ne '') {
+        $rowspan =~ s/^\s+|\s+$//g; 
+    }
+    if ($colspan ne '') {
+        $colspan =~ s/^\s+|\s+$//g;
+    }
     my %config;
     if ($align ne '') {
 	$config{'halign'} = $align;
     }
-    if ($colspan ne "") {
+    if (($colspan =~ /^\d+$/) && ($colspan > 0)) {
 	$config{'colspan'} = $colspan;
     }
-    if ($rowspan ne '') {
+    if (($rowspan =~ /^\d+$/) && ($rowspan > 0)) {
 	$config{'rowspan'} = $rowspan;
     }
     if ($width ne '') {