had the same issue some time ago and was going mad... Being on Mac, the following worked for me:
Leave Terminal.app running while flashing the device
Note, older version of the SDK put novacomd in a different location and you would use this command: "sudo /opt/palm/nova/novacomd"
Attempting to install Novacom fails!
OSX 10.6 and Higher
This is due to a recent change in the way that launchctl handles LaunchDaemons, something that Novacomd is part of
Exit out of the Novacom installer, but do not exit the webOS Doctor itself
Rename com.palm.novacomd to com.palm.novacomd.plist
"launchctl unload -w /Library/LaunchDaemons/com.palm.novacomd" (This should return that it was unable to unload. That is to be expected!)
"sudo launchctl load -w /Library/LaunchDaemons/com.palm.novacomd.plist"
You should be able to continue with the doctoring and will no longer need to manually run Novacomd
source: webOS Doctor Tutorial