Try using multiMC and create a new instance for it. MultiMC is almost foolproof to install and use any version of forge, any version of minecraft, any mods (including jar, core, regular, and respacks.) Just plug and play... im telling yah, try it this way, cause it automatically installs forge for you. If the problem still exists then it might be a communication error with something on your computer between minecraft, forge, java, or your graphics. *shrugs*