No answer I am afraid, I am in the same position. Minutes before finding your question I ordered a new tube and starter! The tube in my Belling lights very dimly but only at each end. I tried a higher wattage starter and it tried to light the full width but was not stable. I will let you know what happens when I fit the new tube and starter. Please also see my question regarding main cooker overheating.
Pete, January 2005