I have the same problem. I have two of these newer Fastrack girder bridges (6-81248) back-to-back over a "lake". I do have a small "island" of land to support the center area between the sections.
At slow speed my engine stops at the rail joint between the two sections.
At higher speeds the engine will go over both bridges.
I intend to check the continuity on the center rails this weekend to see if the "fix" by bending the center rail tab will work.
Please post if you have talked to Lionel and they have offered a suggestion. I will also try to call Lionel if I cannot find a solution.
BTW, the rails are not as bright a silver color on these bridges than is the rest of the Fastrack. The rails on the bridges are a more of a matte color gray. I have cleaned the rails several times which seems to help temporarily but not for long.
