I use a lite on LTR-52327S burner and everytime i burn at the max speed i get wierd looking burns when looking at the underside of the cd.
It looks dark for around 1 cm (10mm) then light for the rest of cd, tried different type of media and the results are the same if burned at high speed, but if i set it at 12x the cd looks fine underneath.
Only owned for nearly a month.
Ps: sorry for the poor looking picture but should explain clearly the above. (the yellow/red tint was added to the picture so it looks more clear)