weird boot with MCL 2.0

[Katzenstein Lawrence K <katznstn@coral.bucknell.edu>]

Hi
  I'm currently running my MCL 2.0 on a Mac SE with 5 megs of RAM 
and an 80 meg hard drive. The operating system is system six. After I 
installed the package, I put the ptable file in my system folder as
per the manual. However, whenever I boot the system the ptable folder
comes up with an X across it. Also, my own code and the sample code
isn't running right. What's up? Do I need system 7 to run this, or is
there something simple that I should know about.
Thanks
Larry Katzenstein