USAGE

• Copy the script to your webserver.
• Edit the script and change the variables to match with your setup
• Give execute privilege to the owner of the script (chmod u+x upgrade-restore-drupal7.sh)
• Execute the script ./upgrade-restore-drupal7.sh

UPGRADE

$ ./upgrade-restore-drupal7.sh 
 Please enter your choice:
 1. Update drupal
 2. Restore an old installation from backup
 3. Exit
1
Please enter the new drupal version (eg: 7.15) : 
7.18
Downloading drupal-7.18
Downloaded the the drupal version drupal-7.18
Current site backup is created: /home/foo/backups/08-01-2013-0938
Database backup created: /home/foo/backups/08-01-2013-0938.sql
Site is in maintanence mode now
Removed all drupal core files from destination
Copied the new version contents
Drupal updated to drupal-7.18
Site is active again, but please update your database, please visit http://<yourwebsite>/update.php to finalize the process
Removed the source files

RESTORE

$ ./upgrade-restore-drupal7.sh 
 Please enter your choice:
 1. Update drupal
 2. Restore an old installation from backup
 3. Exit
2
List of available backups
08-01-2013-0753
08-01-2013-0758
08-01-2013-0804
08-01-2013-0841
08-01-2013-0849
08-01-2013-0858
08-01-2013-0900
08-01-2013-0904
08-01-2013-0905
08-01-2013-0938
Please enter the backup file name to restore: (eg: 08-01-2013-0753): 
08-01-2013-0905
Site is offline now
Removed production files
Restored the filesystem backup 
Restored the database
Site is restored

View on github

A work around found for this issue is :

Edit : functions.php

add_filter('pre_get_posts', 'query_post_type');
function query_post_type($query) {
if(is_category() || is_tag()) {
$post_type = get_query_var('post_type');
if($post_type)
$post_type = $post_type;
else
$post_type = array('post','custom_post_type_name','nav_menu_item'); // replace custom_post_type_name with your post_type, and keep nav_menu_item to display menu in category page.
$query->set('post_type',$post_type);
return $query;
}
}

Reference: http://wordpress.org/support/topic/custom-post-type-tagscategories-archive-page

Thanks to paranoid  for guiding to the fix .

./arun