Lite-on problem
 

I have a new dvd writer - Lite-on (I'll find out model number later) and it cannot be set to write on lower speeds than 6x (respectively 4x on dvd-rw). Is there any way to fix it ?

Not that i know of. Alot of the newer burners no longer burn at slower speeds. I have a older lite-on that dont burn slower than 4x.

Try updating the firmware for your model. Hopefully there is an update available for yours and if not there might be another that will work.