We have been having issues with the stitches on our Duplo - The snail cartridges. We had an engineer in who took a look at it and said its not the machine its the cartridges and they know about it. He went through our cartridge stock and picked out 2 and said they are the only good ones. We have run both these cartridges without missing a stitch. As soon as they ran out and we replaced the cartridges and it wouldn't stitch again. The machine is basically useless without the proper cartridges - the bad ones come direct from Duplo!. Has anyone else had this problem and if so do they have a supplier they can recommend for the cartridges. We are actually looking at having to replace the machine because of this issue which seems extreme!