Hi Matt & oberonop,
It would seem that I have a similar issue (see my post at http://www.infopathdev.com/forums/p/6880/25080.aspx#25080). Essentially I have an InfoPath 2003 managed code form (VS 2003 .Net 1.1). Recently the .Net Framework 2.0 and .Net Framework 3.0 upgrades were installed on my system by our IT and that appears to be when the fun started. I have seen posts saying that we get this error when both InfoPath 2003 and 2007 are simultaneously installed on the system but I only have InfoPath 2003 installed.
I am wondering if anyone knows if the "bad part" of InfoPath 2007 (which causes the problems with an InfoPath 2003 installation) is actually part of the .Net Framework 2.0/3.0 upgrades? If so, this would explain the sudden and odd behavior but I haven't seen any explicit statements to this saying they are incompatible with InfoPath 2003 managed code templates.
Thanks
Tony