Did you hear back regarding your inquiry? I'm having a similar issue with infopath not allowing me to insert screenshots directly into infopath rich text boxes in the form. I have to take the screen shot save it to the desktop as a image file then either insert the image or open it in IE and copy/paste it into infopath, at which point it works.
It doesn't give an error when it won't paste, it just doesn't even give you the option to paste. I hope someone has come up with a solution, I've been trying to figure this out for 3 days now.