At the beginning of this riding season I've noticed that the needle on the fuel gauge is going back and forth about 1/8 to 1/4 of the dial. Goes towards Empty when I accelerate and towards Full when I break.
Things to look at would be the fuel gauge itself, fuel sending unit and all the connections between the two. If it is an acceleration/decel issue, it might just be a connection that is causing it.
Whale you find a cure? I have a '06 FLHT doing the same thing. Also, never reads below 1/4 tank unless under hard acceleration. Seems to read correct then, left off and cruise and needle raises back to 1/4 tank or so.....?