I bought my AFPD about the same time that you did and I too experieced similar problems after a couple of months of use. I did get a replacement cable and if you want to do that give Fred at Ikarus a call. However, I had a similar experience with the replacement cable - though it was trouble free for much longer time. I suspected that static electricity might have something to do with and so I tried a ground strap. No problems since. It is a pain to wear it when usinig the sim but it seems to work - at least for me. If you want to give it a try you can get a ground strap at Radio Shack. Just clip it to the PC chassis.
Good Luck