Problems with adding mods

[Finley Beddows]

Ok so a while back I got voltz and decided that I needed some kinda automated mining system so what i did was took the main buildcraft mod straight out of the tekkit lite mods folder and put it into my voltz one and BAM! I got quarrys and engines. I played for a bit and thought: "What if I could get other cool mods in this like IC2 and redpower (not EE cause I think its a bit OP)" so did the same thing and it didnt work. then i opened the mod zip folder for IC2 and put all of the class files into "modpack.jar" file and the zip folder in the mods folder. This didn't work so I though hey ho can't have everything in life. Then I realized the horror of redstone compared to redpower wiring and really really like desperately needed redpower. So i did the same for IC2 and got the following mod files and synced them with my modpack.jar folder: RedPowerMechanical-2.0pr6, NEI_RedPowerPlugin 1.4.3, RedPowerCompat-2.0pr6, RedPowerCore-2.0pr6, RedPowerDigital-2.0pr6. Then I put those folders in the mods folder I got this message: "Forge Mod Loader has found a problem with your minecraft installation You have mod sources that duplicate with your system Mod Id : File name" and a list of loads of redpower mods. Help please