Harshk,
IIO is Immigration Information Officer. Basically he/she is kind of customer representative for BCIS who answers calls from applicants. They are not actually AOs (Adjunction Officers) who actually make decisions on your case. From my observations on this forum, IIOs rarely give useful information and many times wrong or misleading information.
If you filed your case at VSC, the number is (802)527-4913. You have to dial many times to go through the busy signal and hold for a long time in order to speak to IIO for several minutes. Have you case number and A number ready before you call.
Call the IIO to verify and update your address in addition to AR-11.
Currently the processing speed is slow. Now officially BCIS @ VSC is processing I-485s received on 12/3/01 or earlier. Many people reaches 540 days without approval. Unless you are extremely lucky, now the average processing time is ~500 days. My case was filed on 11/30/01 and still waiting. Unless VSC takes some serious actions to speed up, the waiting time will be longer and longer.
Keep browse the forum for another month and you will have more ideas about what people are talking about.
Hope this helps.