I just had this happen to my Foldylock and I live in NYC. It snowed about a foot, then rained, then temperatures fells to about 8 degrees F. Lock mechanism would not turn. Used Wd40 not luck. Banged it to hell with a hammer, no luck. Then Wd40 again and it worked. The locking mechanism is operating smoother than ever now. Seems like the mechanism may have frozen or gotten dirty inside and stuck. Since the lock has no mechanism to keep water and dirt out, likely got jammed up. I use it to lock my front wheel of my VESPA for street parking and I liked the foldylock since I could fold it, put it in the storage compartment when I ride and lock it up where ever I want. I'll be contacting the manufacturer to see if they will replace it for me. I don't trust that this lock won't let me down again.