So it's a rare. Not a unique then. When a unique ring drops after a nagel, it won't be a nagel.

You can't say a unique ring drop drops as a rare. You'd have no way to even know if it's a failed unique or just a rare.

You're correct. It might have been a bit confusing. I was trying to say that if the game selected the ring to be unique and rolled a nagel for the second time, then it would be replaced by a failed unique ring instead (although there is no way to tell, in the end it does not matter, the ring will be rare).
Of course, if a unique ring drops, it won't be any other unique that has already dropped this game. But there is no real way of consistently improving your odds of finding a specific unique (other than searching in the most likely places) since all the possible rolls are taking into account after each drop.

Runs of: andy NM, duriel NM, meph NM. New game. Make sure andy and duriel are quest drop bugged.

Quest bugged?

Yeah, google it.
Bugged quest means that boss will drop 1 item more than usually.

not correct definition of "quest drop"

You have a "no-drop" chance on every of the 5-6 treassure classes if you kill andy without quest bug. On a quest drop all the tc's will drop 100%

And the so called "junk-treassure class" including bolts, arrows, etc... is forbidden on a questdrop.

bots man, bots!

go read this: http://forums.d2jsp.org/topic.php?t=76824872&f=87

quite interesting