Yup it's the one and only original.
Putting a small piece of paper under it does seem to help a little bit, but still not completely.
Meanwhile I have contacted the seller FineHine (from eBay) and he said that he could fix that, and if not he would send it to repair himself
I think my Zippo is in good hands because he sells like thousands a month and 100% feedback
Still don't like the 'misleading' description of the Z-Plus, it just doesn't fit every Zippo I guess.