Almost all my spydies are solid. my regular Delica 4 (the beater knife) had small up and down blade play. I disassemble and reassembled it, it ended there. Today I had to clean my Delica 4 for dropping it in salt water and I had to disassemble and reassemble knife again for scrupping, cleaning and oiling and preventing rusting. It had small up and down blade play again. This time I used method I've used to Fix my Buck knives: very small drop grazy blue on need and carefully apply it on lock's tip very thinly let it dry: voilá lock is solid as mountain. However this might be temporary thing. Has worked for me though.