I have ordered 12 boxes of 510 cartomisers (soft/hard tip & LR) together with 2 Riva kits. When i screw the 510 cartos into the Riva, it only goes half way in. Tried it with both hard and soft tip also wont work. I got another batch of 510 cartos which was ordered 3-6 months ago and it works with Riva. Please help as i do not know what to do with the cartos.