Regarding the fuel pump issue, read here! :
http://www.bmwblog.com/2010/10/13/class-action-suit-on-bmw-n54-turbo-engine-for-defective-high-pressure-fuel-pumps-and-turbo-chargers/
This happened to my car the day after I had it! Booked into the dealer and they ordered a new part (at the time they never disclosed what!) and it's been fine since. Looks like it's was a continual problem.
Mentioned on this thread was a software fix. I found this an interesting quote:
"Plaintiffs allege, however, that rather than repair the defective turbo chargers, BMW implemented a secret ’software fix’ to hide the problems from consumers. Any time a consumer brought their BMW in for repair or routine maintenance, BMW would ‘upgrade’ the vehicle’s software. This software tweak kept the turbo chargers from operating at full capacity, ensuring that their defects would go undetected."