A few months ago I had a problem with the brakes on my 2005 S-Type 3.0. I pulled away and nothing happened when I pressed on the brake. I panicked, pressed the brake again and it worked. It's been ok since and I've had the car serviced, but it happened again yesterday. Both times the car hasn't been driven for a day. I checked the brake fluid level and it's ok. Could it be something sinister like the servo. I need to book it into a garage to get it sorted, but I'm nervous about driving it now.