At first, there were some Jewish people who tried to join the Nazi party because that was the only way one could own a business in Germany in the late 1930s and Early 1940s. It was common practice for many Jews to do all the same things that their German counterparts did... to essentially become better Germans than the Germans in order to become successful. For the entire prior century, that tactic had worked quite well for German Jewsw, so they thought to keep doing more of the same. Naturally, being Jewish, they were barred entry into the party, and eventually had their rights eliminated through the Nuremberg Laws.
Later, there were some Jews who became pupets of the Nazis while in the camps. They became informers in some cases. In other cases, they were the straw-bosses for the Nazis... the go-betweens who took the orders of the Nazis and carried them out on their fellow Jews. They were called Judenrate (Jewish Council) or Judendienstordnung (Jewish Police).
Some did it because they thought that it was the only way to survive. Others, some of the more cruel ones, did it because they liked lording it over their fellow Jews. The rest of the Jews were forced to grovel at the feet of these straw-bosses for their very survival. These straw-bosses often chose who did which jobs and which Jews were no longer fit to work, which sentenced them to the gas chambers. Naturally, not all of these straw-bosses survived either... the Nazis didn't really care which Jew they were killing. Some did survive, and there are stories about how some of the more cruel ones were hunted down and killed in revenge later on in life.
Some of them did whatever they could to help their fellow Jews and were recognized by their co-religionists as heroes. Once such was Itzhak Stern, the character played by Ben Kingsley in Schidler's List. Stern assisted Oskar Schindler in making his list of Jews that would be saved, and helped Schindler make sure that none of the ammunition he was "manufacturing" would ever work. Stern was the go-between between Schindler and the Jews he saved, and the man that Schindler trusted to help him choose who to save. Stern used his position as Schindler's straw-boss to help Schindler save hundreds of Jews. He is credited as the man who actually typed up the list of Schindlerjuden (Schindler's Jews).
So the answer to your question, Chou, is that there were in fact some Jews who worked with the Nazis. Some did it to survive. Some did it in order to lord it over those who's lives they controlled. And some did it in an attempt to save their fellow Jews. And I would not be surprised to learn that some Jews were just dupes and didn't know any better.
So the statement made on the other board was factually true to a point. The Jews were never allowed to be Nazis... that right was reserved for Aryans only. But there were some who, for whatever reason, did collaborate with the Nazis, either to survive, or to help others, or becaused they liked the power of making others beg for life.