GSA-4120B with A111 firmware produces coasters ad nauseam

Hi, my GSA-4120B with A111 firmware and laterst Nero produces coasters. From 10 attempts i got 2 times success - back of approx 4000 JPEGs from my digital camera. When i tried to burn backup of huge files (hundreds of megabytes) in got always tracking or focus error… After it burned some 50-55 per cent in most cases sometimes 70 %
Tried all the firmwares from A102 up to A111
Any advice ?

What media? Crappy media most likely are responsible for bad burns.

my A111 so far no issues.

dun blame LG4120. use a proper media to burn.