vst are played in the right side

I bought cubase 7.5.1 before 4 mounh
in the lest week

  1. I Open new project
  2. I load nexus 2 orginal!!! vst
  3. I draw midi
  4. I listen only in the right side
  5. whan I mixdown the chhanel and put the audio mixdown back to the cubase I see that only the rigat side was on the output

I need your help I have a lot of work in this summer days
thank you and I am sorry about my english

I would suggest updating to 7.5.2 from http://www.steinberg.net/index.php?id=downloads_cubase_75&L=1

If you load Halion Sonic SE and set it to a piano sound, do you get playback in stereo?