Duplicate Midi Output Ports - Cubase 64 bit + Rewire/Reason

Just started using the new 64bit version of rewire and every time I create a new instrument in reason I get 2 midi output channels/ports appearing in cubase as midi output devices. Only one seems to trigger the reason instrument.

Anyone else get this? Any ideas why this is happening? Does that happen with the 32bit version?

Apologies if this is an dumb question/old/RTFM issue!