I'm using Comodo Firewall, which doesn't seem to cause a problem on my desktop PC which is running the same version of WindowBlinds.
It doesn't seem to matter which theme I use it just doesn't run, the laptop is a brand new Acer, I can't see anything else running that alters themes.
I don't know if it was the right thing to do or not but putting wbload.exe into the startup folder does make it start on boot.