Lite-on LH-18A1P wont burn TY media

i just got this drive. its installed DMA is ok. drivers ok.reads ok plays ok but when i got to write to TY media i keep getting a error of bad media.(useing clonedvd2&nerorecode2 when i get this error)..ive wasted 7 8x+r ty's. i did get 1 good burn with the TY's useing nero express... the 8x+rs burn great on my 16x liteon.... anyone have any idea what might be going on here...other than i might have gotten a bad drive???? which it is on the verge of being sent back..... thanks for any info/help