Try this : <center>ng code</center>
Worked for me. As a beginner I was stumped and then realized I can switch in my home page view to HTLM where the NextGen shortcode was wrapped with HTML. Here is what I used:
<center>[slideshow id=5 w=320 h=240]<center>
Thanks jbculpepper.
I know nothing about entering code but this worked for me too. simply enter ‘<center>’ either side of the slide show id in the html so it looks like this
<center>[slideshow id=11]<center>
and it positions the slideshow in the middle of my page.
done.