--- loncom/xml/londefdef.pm	2010/11/13 01:43:01	1.403.4.3
+++ loncom/xml/londefdef.pm	2010/11/18 18:07:02	1.403.4.4
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Tags Default Definition Module 
 #
-# $Id: londefdef.pm,v 1.403.4.3 2010/11/13 01:43:01 raeburn Exp $
+# $Id: londefdef.pm,v 1.403.4.4 2010/11/18 18:07:02 raeburn Exp $
 # 
 #
 # Copyright Michigan State University Board of Trustees
@@ -2703,14 +2703,20 @@ 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 '') {