This is almost always do to the fact that you're using a "filtered html" input filter.  You can either change to full html, or you can add the list of tags that you're interested to the list of allowed tags in the filtered list. 
 
Go to "administer ->input formats" then either change your defaults from filtered HTML, or click on the configure link to change the filtered tags.

Dave


From: support-bounces@drupal.org [mailto:support-bounces@drupal.org] On Behalf Of Abhishek Nigam
Sent: Tuesday, January 24, 2006 9:16 PM
To: support@drupal.org
Subject: [support] Disappearence of tags

Hi!
 I'm facing a peculier problem.
  Whenever I embed some of the tags from my side such as name tag , list tags etc they are lost/disappearing on reopening of that particular node page.Is'nt there any way to retain those tags. 
 
Regards!
Abhishek Nigam
Enabling Dimensions (I) Pvt Ltd.
M:9810986314