I have been deploying LNM since Dec 05 and have tackled many issues with it.
By far the biggest problem is hardware compatability.
If the system is not wholly supported in Server2003 SP1 and all components on the hardware compatability list you may well experience issues during the automated server build process.
This led me to look into other processes for system building.
Lets face it most people here are capable of setting up a 2003 server from scratch so....
I setup a new LNM box on hardware I know works.
At the end of the GUI stages after all of the files have been copied to drive D: I stopped the LNM process.
I transferred all of the files from drive D: to an alternative location (USB HDD)
Now I just setup the Servers as normal, run dc promo as required, copy all of the source files to drive D: and resume the installation by clicking on the appropriate batch script.
Works for me, I have done several new builds in this manner without all of the issues related to chipset drivers, NIC's and video that can cause an LNM build to go screwy.
If you have the time try it, I now have all of the files on a DVD with a batch to copy the folders from dvd to D: and resume LNM setup.