Well, I consider about excel output limitation.
So, I'll change code as following:
--- export.php.~1.5.~	2009-06-01 10:34:46.000000000 +0900
+++ export.php	2010-03-19 11:36:45.845650519 +0900
@@ -33,10 +33,10 @@
     $max_sect=max(1,intval(40/$max_rows));
 } elseif ($xoopsDB->getRowsNum($result)==1) { // only one page
     $max_sect=1;
-    $max_rows=40;
-} else {
-    $max_sect=5;
-    $max_rows=8;
+    $max_rows=eguide_form_options('excel_max_rows', 0); // max line output
+} else {				      // multiple sections
+    $max_sect=eguide_form_options('excel_multi_sections', 5);
+    $max_rows=eguide_form_options('excel_multi_rows', 8);
 }
 
 $sheets = array();
@@ -107,6 +107,7 @@
     while (count($rows)<$max_rows) {	// minimum line padding
 	$rows[] = $blank;
     }
+    if ($max_rows==0) $max_rows = count($rows);
     $time = formatTimestamp($edate, 'H:i');
     $sheets[$tab]['rows'][$time]=$rows;
 }
This change make excel output to variable length.
If you want fixed length limitation, set option variables like "excel_max_rows=40" at preferences.

NOTE: This change effect for not changed templates.