Probably the codecs. Poser defaults to Microsoft Video 1, which was horrible even back in 1992. The Cinepak codec included with Windows is almost as old, and not much better. I'd recommend Huffyuv or Lagarith for lossless compression and editing, and DivX or XviD for final work.

... a free plugin download from e-frontier that I could use to take my poser files into max ....

Your tutor might be thinking of the free plugin for Rhino, which was released recently.

http://www.e-frontier.com/article/articleview/1745/1/742

The Max hosting plugin is now developed by Reiss Studio, and sells for about $180. The other alternative is GestureMax, which is even more expensive.

You might find HABWare's free plugins for 3DS Max (OBJ2MAX, MAX2OBJ) useful.

http://www.habware.at/duck.htm