Another MIDI victim

hehehe.......
Looks like a simple connection issue.
Forget the USB.....hook it up like this:
MIDIsport (MIDI) OUT--------->Virus IN
Evolution (MIDI) OUT --------->MIDIsport (MIDI) IN
Make sure you follow all settings to use Virus with a sequencer (read manual)
Make sure Evolution is transmitting/recieving on MIDI channel 1, and Virus the same.
Make sure Cubase is optimised (ie MIDI "Thru" enabled, no MIDI filtering etc) or better yet, upgrade to SX2/3 (You wont regret it!)
This setup however, wont let you record any knob movements from the Virus. I would advise getting a multi-port MIDI interface, to provide for the possibility of more synths etc
There are lots of ways to do this, I hope my way works for you
Good luck!