One of my miners is relatively low powered and becomes disabled by the time the difficulty reaches an acceptable number. I've read the site about setting difficulty and using the workers password. I'm using BFGminer 4.4.0 and it doesn't display the difficulty as the standard 64, 128, 256, etc... Rather, 15m, 3m, 976u, etc... I'm guessing I'm just going to have to play with numbers, but does anyone know how these numbers correlate?