I'm having the same problem. Can't delete News or Pages articles. Hovering the mouse cursor over the delete image shows "javascript:confirmDeleteImage('admin-news-articles.php?del=8','Are you sure you want to delete this article? THIS CANNOT BE UNDONE!')" but nothing happens when i click it, nor can i delete the page from within editing the article.
Internet Explorer shows the following...
Webpage error details
User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0)
Timestamp: Thu, 3 Jun 2010 13:21:08 UTC
Message: Object doesn't support this property or method
Line: 22
Char: 4
Code: 0
URI: http://localhost/zp-core/zp-extensions/zenpage/admin-news-articles.php
Message: Object expected
Line: 1
Char: 1
Code: 0
URI: http://localhost/zp-core/zp-extensions/zenpage/admin-news-articles.php
I believe the problem started after upgrading to 1.29, not sure though.