Despite Scientologies claims to being compatable with Judaism- it is completely incompatable! Its beliefs are completely foreign to Judaism and a bit of research will show them to eventually deny the existence of G-d (look up OT 8 or OT VIII You should be able to find it online somewhere). Hubbard pretty much tried to deify himself in the religion while bilking as much money as he could from his followers- the end result is that scientology IS Idolatry for a jew and completely forbidden to a Jew. I am well aware that the early materials seek to disguise this fact, as well as being aware that they claim it is compatable with all religions- but do your research and you find a completely different story!
(Yes, I was one of the critics they tried to spam out of existence in the early 1990s in alt.religion.scientology whats funniest about the whole internet critics vs Scientology saga is that if the Church hadn't tried to shut down alt.religion.scientology and hadn't been so aggressive in their attacks on critics on the web, then the critic movement probably would have died and never bothered them. However, one of the doctrines taught by Hubbard was to "attack and never defend"- all they did was follow their deities words and ended up creatign a huge nightmare for themselves.)
ex-scientologist, ex scientology critic (yes, those two frequnetly go together! LOL); www.xenu.net, www.xenutv.com