DC backups with liteon 24/10/40

[bertelo]

Hi
I have a liteon 24/10/40 cdrw burner with the last firmware (s59), and about 4 out of 5 DC backups I burn (from internet or copies) just don't work or work very bad inspite of using Verbatim CD-r's

I write at 8X (i can't under but i would like if someone knows how i can do that...) with disgjuggler with these settings : mode1n offset0, 2352, cdXA.

Could someone help me?
thanks