Crystal Reports 2008 not working when compiled with Visual Studio 2010

Our application runs Crystal Reports in process. We have a C# interface which handles that data transfer to Crystal 2008. This has been working well for us when until we moved to the Visual Studio 2010 compiler. The calls to ReportDocument.OpenReport() work without any errors but when it gets to ReportDocument.SetDataSource(DataTable dataTable) it throws this exception.

Mixed mode assembly is built against version 'v1.1.4322' of the runtime and cannot be loaded in the 4.0 runtime without additional configuration information.

at System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks)

at System.Reflection.RuntimeAssembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks)

at System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection, Boolean suppressSecurityChecks)

at System.Reflection.RuntimeAssembly.InternalLoadFrom(String assemblyFile, Evidence securityEvidence, Byte[] hashValue, AssemblyHashAlgorithm hashAlgorithm, Boolean forIntrospection, Boolean suppressSecurityChecks, StackCrawlMark& stackMark)

at System.Reflection.Assembly.LoadFrom(String assemblyFile)

at CrystalDecisions.ReportAppServer.DataSetConversion.DataSetConverter.?(IntPtr)

I have a runtime installation of Crystal Reports 2008 on a 32 bit Windows XP machine. Do we have to handle data differently when compiling with VS2010 or is there another version of the runtime that solves this problem?