Heh yeah was about to come in and say i figured it out. You are right, i thought about what new additions you made to the latest version, then realised you added Neoscrypt and Lyra etc. I had already manually created them, however i called it Neoscrypt, you called it Neo Scrypt. It took exception to that. Wouldnt let me delete one within MultiMiner, had to edit the xml manually. Removed my one and it did the trick, All operating.
(Not sure why id would stop me starting the miner, as I was using x11 and not Neoscrypt...)
Thanks for the details - sounds right. My guess is that, when I merge custom and built-in algorithms I'm doing so case-sensitively (which I shouldn't). I'll fix it when I'm back.
As far as what triggered the error when you were mining X11, MultiMiner downloads all necessary miners before starting mining. This is because something (such as Auto-Mining Strategies) may switch your mining later. It was downloading the required miners that led to the error.