OK but are the assembly references in your app the same version 12? Must also be the full Framework client.
CR 2008 does not have 64 bit assemblies, you ahve to move to VS 2010/2012/ or soon 2013 and CR for VS to get 64 bit support and runtime.
Because CR 2008 is 32 bit only make sure to set your app properties for x86 mode only and not AnyCPU.
Check the Overview tab for the installer and redist packages.
Don