Page 1 of Panasonic E-85 Recording problem

I`ve had a Panasonic E85 for over 6 months. Had no problems using TDK 4X DVD-Rs.
Starting using TDK 8X DVD-Rs recently. Having problems with these. The machine sometimes shuts down during FR recording. Also, machine shuts down if I try and choose my own thumbnails. Has anyone else had similar problems? I`m still wating for feedback from Panasonic and TDK. It still works fine with 4X media.