Hi! This is my first post here, I usually haunt the Pinnacle, DV.com or DVDRhelp forums.
I just bought a NEC ND-2500 (Built Feb 04, 1.06 FW) and will spend much of my time in the NEC forum, even though THIS question is of a general nature.
The OEM primary drive of my 4-year old PC was a Pioneer DVD-ROM, which I retired a few years ago due to a loud CLUNK CLUNK CLUNK it made, lasting for a few seconds up to several minutes, any time it was first reading or seeking another section of a disc. This noise presented with all discs, whether pressed or home-burned, CD or DVD, and sounded severe enough to be causing damage to the disc or mechanism.
The NEC 2500 now resides in its place and makes the same type of noise! (Although the noise is dampened enough to sound normal and non-damaging in this case, and lasts only for a few seconds each occurance).
So... is it normal to hear a seek clunk in all DVD drives? Perhaps the noise in my OEM Pioneer drive was normal, just louder because it was new technology back then...
I have never heard harsh mechanical seek noise in a CD-ROM or CD-RW drive.