I ran into the same thing some time ago.
You can get it to work if you change PLA-support to PLA as I remember.
After a while I gave up on reprap host and moved over to skeinforge from makerbot.
I just could not get reprap host with it's 5D Gcodes to work with my Gen 2 electronics no mater how hard I tried.
Good luck
Stephen
Edited 1 time(s). Last edit at 12/14/2009 01:39AM by stephen george.