Well, it does seem to be a 64-bit issue after all. I checked MSDN for this, and found this link
http://msdn.microsoft.com/en-us/library/ms141766.aspx
When I run the dtexec, I get the errors. When I run the dtexec from the 32-bit folder(C:\Program Files (x86)\Microsoft SQL Server\100\DTS\Binn), it runs fine.