A number of customers have come back to us saying that error messages pop up when attempting to browse metadata in Visual Studio (the message being something to the tune of - "the binding could not be loaded"). Most of the time, it is due to the proper client libraries not being present. Irrespective of whether your target SAP system is Unicode or not, the adapter always requires the Unicode version of the RFC SDK (i.e., it requires librfc32u.dll).
I've attached the source code of a small project which simply calls two APIs in the RFC SDK. If the program runs fine, it means your SAP client libraries are in order. Note - the machine type is set to X86 in the Project Settings - you should change this to X64 if you want to test it out on 64 bit. You also need to set the "Additional Libraries Directory" path to the folder which contains librfc32u.lib. The .zip file also contains the X86 executable of this program. For 64 bit, you'll need to re-compile.
It also doesnt hurt to make sure you have the Visual C++ Runtime dlls:
http://www.microsoft.com/downloads/details.aspx?familyid=200B2FD9-AE1A-4A14-984D-389C36F85647&displaylang=en (Visual C++ 2005)
http://support.microsoft.com/default.aspx/kb/259403 (Visual C++ 6)
(download and install both)
http://www.microsoft.com/downloads/details.aspx?FamilyID=EB4EBE2D-33C0-4A47-9DD4-B9A6D7BD44DA&displaylang=en (Visual C++ 2005)