I'm waiting now since late Sept/ early Oct for an answer to my claim. It has been suggested that I call up and find out what is going on, who should I call? My case worker, or one of the adjudicators?

When I applied for disability It took 4 months once all the paper work was in for them to make a determination. It also has taken 4 months to do a review. So I would say you have a few more weeks to go before you should hear from them yet. I would give it till the end of Feb. then if you haven't heard anything call the local office. The number should be in your phone book or call information to get the office closest to you. Or go to there website ssa.gov and see if they have any phone numbers there.