What was Oracle hiding from? All of the things that were trying to get her (the outcasts) were around at the time of the first movie. Did they, in the 6 months between #1 and #2, just decide that they wanted to kill the oracle?
With the machines getting closer to Zion and the humans in more trouble than ever before, one can assume that the Oracle didn't want to expose herself too openly and allow humans to be susceptable to attack. However, now knowing that the Oracle is a program, it's possible that her disappearance was a ruse on the part of the Matrix itself.
Dames