You made it! I took sample from ''InfoPath Team Blog''http://blogs.msdn.com/infopath/archive/2006/12/18/creating-complex-infopath-controls-in-c-sharp.aspx
and InfoPath 2003 crash in preview (Bhuuuuaaaa)
My C# control work properly as long as I don't try to implement InfoPathControl interface. If you could send me your code on Email.
Thanks.