Setup Help - No Sound w/NI Elektrik Piano in Cubase SE

I have been unsuccessful in setting up NI Elektrik piano (registered version) and generating any sound on my computer. I have a Roland RD-300SX going to a Lambda into a new Dell running Vista (could be the problem). The keyboard sends and records midi signals but on playback (or live) the midi output when pointing to the NI instruments do not generate any sound. The Vista drivers for the Lambda from Lexicon were first released in late 2007. I am using Cubase SE. I have no problems generating sound with other 3rd party VST instruments. I have the same issue with a demo version of B4 II. I am unable to create sounds with both NI instruments in the stand-alone version as well. I sent an email to NI Help Desk on 02/22 but have not received a response back yet. I also searched their Knowledge Base which was limited as well as Googled the internet but have been unable to find anything. I am hoping this is a simple setting but I am posting here hoping for answer.