When I was a full on dub I disagreed with many of the teachings (mainly the one that only JW's would be saved, although the supposed fulfillment of scripture by the events that happened to the witnesses in the 19020's didn't at all ring true either). However, when you have the overall belief that you are still the only true religion on the earth then you simply put them all up on the shelf and forget about it all. Until that is, the shelf becomes overloaded and all it takes is one little thing and the whole thing comes crashing down. Some people have bigger shelves than others though.
My mum is still a JW but doesn't agree with many of the teachings but justifies them ALL by saying that God is still using the organisation and that no one else is doing any better than the witnesses. Cognitive dissonance at its finest. She wont educate herself to reach other any opinion but I beleive it is because she has invested too much of her life in the religion and cannot bear to lose her closest friends. Her choice but a frustrating one for us, although we are fortunate that she doesn't shun us or her grandchildren, unlike Besty's mother and brother (although I don't think they have ANY doubts, they bought and paid for the deluxe model of blinkers....)