I will try to be the most clear as possible but sorry I'm not very good in English.
1/ So, I have installed full version of 3ds Max in my 3 slaves machines because for me, doesn't work with only backburner.
2/ I have create a "Homegroup" and shared all my textures map folder (Read and Write).
3/ Launch Backburner Manager in your master machine and in slaves machines launch Backburner Server and double click on Corona Server (Right clic onDrServer icon, Compatibility, check "Run this program as an administrator")
4/ In 3ds Max, go to Asset Tracking and set path of all your textures use in your scene.
It's very important to set path like this: Network/name_of_your_computer/name_of_your_shared_folder/sub_folders
for me: Network/AJ/RESSOURCES_3D/SHADERS
5/ After, I think you know ;) Render Setup/System/Enable/Search LAN/ Render
6/ If doesn't work, return to Asset Tracking and go to Bitmap Performance and Memory and uncheck "Enable Bitmap Packing", restart Max and re launch your render.