More problems with nero cd speed

I have tried all day to get a decent read speed result from my ltd163d dvd rom drive…I tested it a few weeks ago and got the following results: start: 19.85
end: 50.25
av. 38.06
the seek times etc. are not important at the moment because they are pretty similar to what they have always been random 94ms and so on…but my problem today is that once my drive gets to 30x or thereabouts the graph suddenly drops right down to 8x or thereabouts…I noticed in the options that I could set the read speed to max (48x) which made the drive spin up much quicker…the test started off great with the speed reaching up into the high forties however it always dips suddenly towards the end and finishes the test at about 8x-16x which drags the average times down to the mid 20’s…everytime I go back to the options page the read speed is re-set to 32x and not max (48)…the read speed for my liteon 32125s is always correct at 40x and the tests on that drive are ok…the only thing I have changed recently is the firmware to make the drive region free, can I reverse this firmware (it still shows as GHR3) even though the patch has been applied (1211.exe)…dma is ok and the drive works ok its just that it spins down on every disc…any ideas???..cheers chaps…dave

I have noticed also that sometimes where it states the read speed it says P-CAV and other times it says CAV…it slows down with all discs now both pressed and cdr’s…I have reformatted my drive and at the moment all I am running is norton antivirus (which I disable during testing) and nero…I have downloaded the update but it makes no difference both cd speed 85c and 85e act the same (both show the default speed of the drive as 0 until I manually change it to 48 whereas my 32125s drive show 40 read speed as soon as I open the options tab)…is my drive broken??it certainly cant maintain any sort of high speed reading anymore…I have installed the ASPI layer again as win xp pro didnt have it as default…can anyone help please?