I bought the Jot Pro and had the skipping problem.
I ordered two disks from Adonit ($18 with shipping!!). The disks did not solve the problem, so after a couple of mails, they said I could send my Jot Pro back, so they could send me a new one. I then already told them I used toothpaste and was planning to use conductive grease.
After I found out the high shipping costs for the pen, I decided not to send it anymore.
Adonit then offered me to send me two more replacement disks, because I was forced to use the conductive grease.
Now that is some service. Haven't received the disks yet, but I think they will arrive soon.