hi~ golfmann, if the icon/image become to a red X.. usually it just mean a wrong image URL reference.
<input type=""image"" src=""" & strImageUrl & "images/button_mark_all_read.gif"" value=""Mark all read"" id=""submit1"" name=""Mark all topics as read"" border=""0""" & dWStatus("Mark all topics as read") & " tabindex=""-1"">
i think you should remove above line images/ we've already defined the default images directory strImageUrl on Admin Section.
unless you've moved all icon images to /images sub-folder by yourself, otherwise the default images folder should be the same with other .asp files by default Snitz setting.