Since there has been the MCSE thread on the Lite-On forum, why not one for Samsung. TS-H552B and TS-H552U seem to work well with MCSE, but they are not Lite-On drives.
You can read about MCSE first here.
You can find out MCSE-extracted media support lists here for TS-H552B and TS-H552U. 10 firmware versions so far.
I tried to change the speed of RICOH JPN R01 <-> RICOH JPN R03 and the only speed are 2.4x. 
I tried again to change the speed of RICOH JPN R01 <-> RICOH JPN R02 and the only speed are 2.4x. :a
Just to not blame the Arita disk I tried to to change the speed of SONYD11 <-> SONY D21 and ( :a :a ) the only speed are 2.4x.
Any clues about that issue ???
Let us continue the discussion here. Which drive do you have, which firmware did you change and how exactly did you try it ?