It is also possible that your foil end sprockets may not be fully seated in the foil cores, causing a misalignment of one core to the other. Try lightly tapping each core end sprocket with a mallet or a piece of wood to insure it is fully seated.
Since the brand of foil makes no difference - it makes sense the problem is with the machine. The white plastic Z strip is a good place to check. Check that the idler bars move freely. Check the wad of used foil to make sure it's winding evenly. Check the pins and the chrome retainer clip when seating the cartridge to make sure the cartrige is in correctly. :Canada: