eLicenser does not validate license, even though it's there

I was using Cubase 4 all along a Windows Vista PC. I recently bought a MacPro (Snow Leopard), and I wanted to run Cubase on it. I downloaded the latest Cubase and eLicense software for Mac from Steinberg’s website. Both applications install properly without problems. But when I tried running Cubase, it says “eLicenser(s) contain(s) no valid license for this application”, even though the USB dongle is inserted. Yet I can clearly see the Cubase 4 license listed in the eLicenser program. Something is not right here. When I insert the USB dongle back on the PC, Cubase was running happily. I wonder if anybody has the same experience, or has any suggestions. I am new to Mac.