Be more specific. Which tags are being stripped? Since admin posts bypass HTMLPurifier, the code is being cleaned. by TinyMCE.
You can look in the file: /templates/base/scripts/BxBaseConfig.php for the line below:
extended_valid_elements : "a[name|href|title],img[class|src|border=0|alt|title|hspace|vspace|width|height|align|name],hr[class|width|size|noshade],font[face|size|color|style],span[class|align|style]",
You can try adding to that line tag[attribute|attribute|attribute], for whatever is being stripped.
My opinions expressed on this site, in no way represent those of Boonex or Boonex employees.