Following the previous post, the answer was somewhat more mundane. We were heading home last weekend after our engagement party at Laura's folks, and on the slip to join the motorway the car cut out completely. Had to call out the AA and ended up getting a tow back again because (surprise suprise) there was no fuel coming through. The AA mechanic was great and suggested I looked into the fuel line, he personally didn't like externally braided lines because it's hard to see if the underling rubber has perished.
So I returned this weekend with my Dad, a new fuel line (the clear plastic version from ecas), and some tools. We dropped the fuel tank and sure enough the pipe had perished and was letting air in. We replaced it and made up joints at either end using good sections of the old pipe - making sure to put hose clips on all joints as well.
The result? Smooth running again. I think the lesson to learn is definitely that the pipe is the most likely reason for a lack of petrol ("that's obvious!" I hear you say). It's a shame that it's so fiddley to check/replace the joint on top of the tank.