Help Cross flashing

I have Hi-val dvd drive a few month ago, works perfectly with dvd5, cd and such, but not DLdvd, I try and it fell as no player can play, or hang up at layer break. Drive label say drive name as BenQ 1670 build in China, as of April or May. I try flasihng with BenQ firmware but not suceesd. Please guide me way to cross flashing to BenQ if posible.
Thanks in advance,

BenQ DW1670, Sony DRU-820A and I/O Magic (DW1670 OEM) crossflash!

Check post #2 for the instructions.

Thanks ZEVIA, you are super, Cross flash done, just reset my PC, now try to burn some thing as DLDVD.