Slimtype SOSW-833S can't read or write CD's

I have an Acer Aspire 3000 equiped with a Slimtype SOSW-833S.
It didn’t work for a while but i got the VRS3 firmware and it works perfectly but only at DVD’s.
It can’t read or write CD’s.
What can I do about this? I searched all the web for a solution but didn’t found an answer nowhere and i’m trying to fix it for two days now.
I tried VRS4 also and the diference is that it was slower and the LED was blinking in yellow instead of green and still there was no change about the cd’s.
I tested if it is on DMA and it is.
Can someone help me perhaps with an old firmware version?