KCT,
.....

If you can't rotate those pads to better fit your ears, then it's surely a dud! I haven't read about any D5000 fakes and therefore can't comment on them.
Your listening history may well heavily contribute to your impressions of the D5000's.
As to the Markl mods, I'm sure they make a difference, but am not so sure about it being necessarily better. If I'm happy as they are now, then that's all that counts, and indeed I am. The D5000 and the HD650's make for a nice pair to have. Their approach is different and I now use them interchangeably as needed.