I applied for my passport on 29/10/2012 (had my ceremony on 18/10/2012). I used 2, two month old, photographs and they sent me back a request to supply newest photograph (max. 1 month old). This request was sent using second class post, so I got it around 4th Nov. Immediately sent two more photographs, countersigned by my friend (a landscape architect) who had countersigned the form and earlier photos. However, I noticed my friend did not put my title (Mr) on the newer photo's. Apprehensive that they might reject the application, I emailed IPS clarifying this point. Did not hear from them back, though.
Few days later, I received my letter for arranging an interview. I called up the number mentioned on the interview letter and organized one for 21/11/2012. The interview questions I was asked are as follows:
1) Date of my first arrival to the UK
2) My full name with spelling
3) My full address
4) Full name of my wife, previous names (maiden etc.)
5) Her and my birth dates
6) Age of my son
7) My mortgage lender + address of property
Previous addresses (few of them)9) My counter-signatory's occupation
10) Birth dates of my parents
11) Who do I hold my bank account(s) with?
12) Which University did I attend?
13) Names of my parents
14) My credit card lenders
15) Mode of my application for passport (postal, online etc.)
16) Application date for passport (approx.)
17) Citizenship ceremony date and type (private, public etc.)
18) If passport application was smooth (explained the photo situation)
The answers to these questions are already with them, they just verified that I am the right applicant. So the answers have to given out from memory (and no, they don't judge us if we hesitate / take few seconds to think).
After the end of the interview, I was told IPS will contact me in couple of days.
I received my passport today (24/11/2012) by courier.
Hope this is helpful. All the best to others who are waiting.
Cheers
Shre