My fuel gauge used to stick somehow...never bothered to do anything about it so I don't have any wisdom to impart i'm afraid.
I assumed it was linked in some way to the electrical side of things rather than the slender/float sticking in the fuel tank because it used to correct itself every time I stopped the engine and re started it. Never got caught out on a journey, but it could have easily done just that, however, if I hadn't discovered the problem through general observation early on in ownership.
