Note. This is a maximum 8x burner in "normal mode". At most of the time it will burn at maximum 4x even on 16x+ rated media (in "power save mode").
What's the problem. Just get some crap +R media and you are king.
No need spending time for searching for "older" firmware because there is no eSAU108 firmware that will not help you out burning "slower".
"Better be burning at 2x or 1x" is just an old and false myth, (probably from users with first generations of PlayStation trying to burn illegal thingz).
BTW. Reading manual and checking out supplyed CD with applications and drivers might help.