Impersonation limitation is SharePoint 2007 OM

If you are trying to do impersonation using SPSecurity.RunWithElevatedPrivileges remember, SPContext.Current will not work for you. The proper method of using SPSecurity.RunWithElevatedPrivileges in your code for impersonation is:

 

Be sure to create a new SPSite which is the root security reference while you’re impersonating. Here’s a small code snippet:

   SPWeb web = SPContext.Current.Web;
   SPUser user = web.CurrentUser; // the calling user

   // Uses the SHAREPOINT\system creds with the SPUser's identity reference of user
   SPSecurity.RunWithElevatedPrivileges(delegate() {
     // Gets a new security context using SHAREPOINT\system
     using (SPSite site = new SPSite(this.Page.Request.Url.ToString())) {
       using (SPWeb thisWeb = site.OpenWeb()) {
         thisWeb.AllowUnsafeUpdates = true;
         SPList theList = thisWeb.Lists[listName];
         SPListItem record = theList.Items.Add();
         record["User"] = user; // calling user
         record.Update(); // uses SHAREPOINT\system
       }
     }
   });