Hi,
I hope, only for InfoPath forms for 2003->2007 no need of any patch. For opening VS2003 projects with InfoPath2003 template from VS2005 with InfoPath2007, they have saperate connectors. Once try by creating a sample of InfoPath2003 by opening on InfoPath2007.
B.Shiva Prasad
InfoPath Dev,
http://www.ggktech.com
India