Missing Server Tags in a WebForm

[Richard Steele (Basemap)]

VisualStudio 2005 Release
having developed a webform with embedded tags such as

<a href="javascrip t:OpenPopupPage ('Calendar.aspx ','<%= WeekEnding2.Cli entID
%>','<%= Page.IsPostBack %>');">

This page is saved, but when repoened for edit, i am missing the server tags
i.e.
<a href="javascrip t:OpenPopupPage ('Calendar.aspx ','','');">

any suggestions how to stop the tags from being removed
--
Thanks
Richard