There are a number of things that have changed in the SDK from the one you've been using to the latest version.
Something else to look at - the Crystal for VS SDK does NOT play well when installed side-by-side with the older version of the SDK. You may need to install VS 2010 on a VM or workstation where VS 2008 is NOT installed or you may need to just uninstall the Crystal SDK from VS 2008. If you're unable to do either of those, make sure that you have the correct version of the assemblies referenced in your project.
What type of datasource are you reporting against? If it's XML, you have to manually install the driver. Scroll down below the table with the various downloads at SAP Crystal Reports, developer version for Microsoft Visual Studio: Updates & Runtime Downloads. Below the "Warning" message is information about how to do that.
If that doesn't help, what is the exact error you're getting?
-Dell