Can write CDs but not DVDs
 

I have a Plextor 755 dual layer DVD writer.

It writes CDs 100% perfectly but fails about 50% of the time on DVDs, with verify errors. DL DVDs are even worse, failing perhaps 90% of the time.

I had it changed by Plextor but the new unit does exactly the same thing.

Can anybody suggest anything?

The machine is a 2.2GHz PC, win2000, the BIOS setting for the IDE cable has been tried on both Auto and the "133" options. There appears to be nothing else to configure in the BIOS.

I have two SATA hard drives.

I am not getting any underrun error reports, which would be the logical result of some driver disabling interrupts for long periods.

The CRC errors on verify are real, on the DVD.

I have tried different (slower) speeds also.

I would try a different brand of DVD, I had a few ones that wouldn't write past the lead in. Swapped them for something else and worked perfect.