I have an embedded webbrowser inside a windows form. The documentComplete event fires on machines that have visual studio 2003 / 2005 installed, but not on machines that don't. This has also been confirmed by someone else, shown on this thread:
http://forums.microsoft.com/MSDN/ShowPost.aspx PostID=1112619&SiteID=1
has anyone heard of this problem

DocumentComplete event not firing on certain machines...