Regarding the 64-bit system wanting 32-bit support. I don't find it so bizarre:
Although deployed to a 64-bit system, this doesn't mean all the referenced assemblies are necessarily 64-bit Crystal Reports assemblies. Further to that, the Crystal Reports assemblies are largely just wrappers to a collection of legacy DLLs upon which they are based. Many 32-bit DLLs are required by the primarily referenced assembly. The error message "can not load the assembly" involves these DLLs as well. To see visually what those are, go to www.dependencywalker.com and run 'Depends' on the assembly in question, directly on that IIS server.