Sounds like I had a rougher time than most then - I am currently applying for a second passport because my new role involves me travelling to Israel and Arab countries. I checked with the passport office beforehand and got from them details of what needed to be in the letter (list of countries visited/to visit with dates) and was told that it probably wouldn't be enough. I was told off because my boss who witnessed my photo didn't have a fixed-line number (he doesn't use one). I was told repeatedly that a second passport was a privilege and I would be very lucky if I got one (despite the fact that my job will involve trips to Riyadh and Tel Aviv). The passport officer took pride in telling me about a woman who came in the day before for the one-day service and despite three different letters faxed to UKPA from her employers, a second passport was still rejected.
As of now I'm still waiting for the phone call that my application has been approved. Sounds like I may just have been unlucky with the officer I saw.