First, how do you launch your agents? If you run them scheduled, for example, they'll run on the server. If they run from an Action Menu selection or from a button, then they'll run on the client. We want to make sure we know which machine the connector should be set up on!
Perhaps more importantly, it sounds like you have the Unicode version of librfc32, while you do not have a Unicode version of the SAP connector file. Those should match. So for example you should either have:
nsap.dcx and librfc32.dll
or
nsapu.dcx and librfc32u.dll
http://www-01.ibm.com/support/docview.wss?uid=swg21446691