As many people know, once get multiple mods there is an id clash. Sometimes it can me fixed with software. However Minecraft increases the ids of items up by 256. Some mod authors take that into consideration, some do not. Here comes the suggestion...make a method/function something, to assign each item a number through forge...eg: SetItemID(mod:itemname, 1)...the number would be the priority, as some need to be done during world gen, and apparently minecraft can only use the lower values for world gen.