Hi Mark,
Let me get you more details.
I have Windows Server 2008 x64 running with Visual Studio 2008 installed.
For Oracle, I have cleared all my previous installation and even deleted all the folders for previous installation of ODP.NET. After that I only installed the Oracle Database 10g Client Release 2 (10.2.0.4) from the link you gave (I installed all the components) :
http://www.oracle.com/technology/software/products/database/oracle10g/htdocs/10204_winx64_vista_win2k8.html
I have Oracle Database 11g running on VMWare on Windows XP 32 bit.
When I run my WinForm application using code so far so good. I extract data from the HR schema and put them in listbox, perfectly no error.
But when I am trying to create by Add New Data Source... then I hit the:
Attempt to load Oracleclient libraries threw BadImageFormatException. This problem will occur when running in 64 bit mode with the 32 bit Oracle client components
Hope that can give you a better idea.
Ming Man