Hi Scott -
Great news!! I was able to import a Dita Map into RoboHelp on my Vista machine!
Bad news is I am still receiving the same error message on my Windows 7 machine ("Processing with DITA Open Toolkit failed. No Logs found. Check DITA Open Toolkit is installed and working"). Thrilled to have a working environment to play in though!! Can now start incorporating all the tools in the Adobe Technical Communications Suite 2.
Thank you so much for all of your help and direction... I have spent several days trying to get this work using the most up-to-date tools out there. Funny that it works with an older version of OT and no environmental settings at all.
Thanks again!!
Rebecca
p.s.... still going to get to the bottom of the Windows 7 environment though 
Hi Rebecca...
It sounds like you're making progress .. that's great!
That is odd that it would work on Vista but not under Win7. You might try running RH "As Administrator" to see if that helps.
My RH8 is installed on XP .. perhaps someone else running RH on Win7 can report their success with importing a DITA map.
Cheers,
...scott